The Effect of Key Nodes on theMalware Dynamics in the Industrial Control Network

As industrialization and informatization becomemore deeply intertwined,industrial control networks have entered an era of intelligence.The connection between industrial control networks and the external internet is becoming increasingly close,which leads to frequent security accidents.This paper proposes a model for the industrial control network.It includes a malware containment strategy that integrates intrusion detection,quarantine,and monitoring.Basedonthismodel,the role of keynodes in the spreadofmalware is studied,a comparisonexperiment is conducted to validate the impact of the containment strategy.In addition,the dynamic behavior of the model is analyzed,the basic reproduction number is computed,and the disease-free and endemic equilibrium of the model is also obtained by the basic reproduction number.Moreover,through simulation experiments,the effectiveness of the containment strategy is validated,the influence of the relevant parameters is analyzed,and the containment strategy is optimized.In otherwords,selective immunity to key nodes can effectively suppress the spread ofmalware andmaintain the stability of industrial control systems.The earlier the immunization of key nodes,the better.Once the time exceeds the threshold,immunizing key nodes is almost ineffective.The analysis provides a better way to contain the malware in the industrial control network.

Multi-Objective Optimization Algorithm for Grouping Decision Variables Based on Extreme Point Pareto Frontier

The existing algorithms for solving multi-objective optimization problems fall into three main categories:Decomposition-based,dominance-based,and indicator-based.Traditional multi-objective optimization problemsmainly focus on objectives,treating decision variables as a total variable to solve the problem without consideringthe critical role of decision variables in objective optimization.As seen,a variety of decision variable groupingalgorithms have been proposed.However,these algorithms are relatively broad for the changes of most decisionvariables in the evolution process and are time-consuming in the process of finding the Pareto frontier.To solvethese problems,a multi-objective optimization algorithm for grouping decision variables based on extreme pointPareto frontier(MOEA-DV/EPF)is proposed.This algorithm adopts a preprocessing rule to solve the Paretooptimal solution set of extreme points generated by simultaneous evolution in various target directions,obtainsthe basic Pareto front surface to determine the convergence effect,and analyzes the convergence and distributioneffects of decision variables.In the later stages of algorithm optimization,different mutation strategies are adoptedaccording to the nature of the decision variables to speed up the rate of evolution to obtain excellent individuals,thusenhancing the performance of the algorithm.Evaluation validation of the test functions shows that this algorithmcan solve the multi-objective optimization problem more efficiently.

幽门螺杆菌通过Wnt/β-catenin信号通路对胃癌细胞侵袭及血管新生因子的作用研究

目的研究幽门螺杆菌(Hp)通过Wnt/β-catenin信号通路对胃癌细胞侵袭及血管新生因子的作用。方法收集手术切除的胃癌组织并检测Wnt1、Wnt3a、β-catenin、MMP-7、N-cadherin、E-cadherin、VEGF、bFGF、Ang-2 mRNA的相对表达量。培养胃癌细胞株SGC-7901,分为对照组、Hp组、Hp+ICG-001组。对照组用不含细菌及药物的DMEM处理,Hp组用含有Hp的DMEM处理,Hp+ICG-001组用含有Hp及Wnt/β-catenin信号通路抑制剂ICG-001的DMEM处理。采用Western blotting检测Wnt1、Wnt3a、β-catenin、MMP-7、N-cadherin、E-cadherin蛋白的相对表达量。采用Transwell检测侵袭数目。采用酶联免疫吸附试验检测VEGF、bFGF、Ang-2的含量。结果与Hp阴性胃癌组织比较,Hp阳性胃癌组织中Wnt1、Wnt3a、β-catenin、MMP-7、N-cadherin、VEGF、bFGF、Ang-2的mRNA相对表达量均增加(P<0.05),E-cadherin的mRNA相对表达量降低(P<0.05);Hp组Wnt1、Wnt3a、β-catenin、MMP-7、N-cadherin蛋白相对表达量、侵袭数目、VEGF、bFGF、Ang-2的含量高于对照组(P<0.05),E-cadherin的相对表达量低于对照组(P<0.05);Hp+ICG-001组Wnt1、Wnt3a、β-catenin、MMP-7、N-cadherin蛋白相对表达量、侵袭数目、VEGF、bFGF、Ang-2的含量低于Hp组(P<0.05),E-cadherin的相对表达量高于Hp组(P<0.05)。结论Hp通过Wnt/β-catenin信号通路促进胃癌细胞的侵袭及血管新生因子生成。

Prospective study of biofeedback retraining in patients with chronic idiopathic functional constipation

AIM: To determine the efficacy and long-term outcome of biofeedback treatment for chronic idiopathic constipation and to compare the efficacy of two modes of biofeedback (EMG-based and manometry-based biofeedback).METHODS: Fifty consecutive contactable patients included 8 cases of slow transit constipation, 36 cases of anorectic outlet obstruction and 6 cases of mixed constipation. Two modes of biofeedback were used for these 50 patients, 30 of whom had EMG-based biofeedback, and 20 had manometrybased biofeedback. Before treatment, a consultation and physical examination were done for all the patients, related information such as bowel function and gut transit time was documented, psychological test (symptom checkJist 90, SCL90)and anorectic physiological test and defecography were applied. After biofeedback management, all the patients were followed up. The Student′s t-test, chi-squared test and Logistic regression were used for statistical analysis.RESULTS: The period of following up ranged from 12 to 24months (Median 18 months). 70% of patients felt that biofeedback was helpful, and 62.5% of patients with constipation were improved. Clinical manifestations including straining, abdominal pain, bloating, were relieved, and less oral laxative was used. Spontaneous bowel frequency and psychological state were improved significantly after treatment. Patients with slow and normal transit, and those with and without paradoxical contraction of the anal sphincter on straining, benefited equally from the treatment. The psychological status rather than anorectal test could predict outcome. The efficacy of the two modes of biofeedback was similar without side effects.CONCLUSION: This study suggests that biofeedback has a long-term effect with no side effects, for the majority of patients with chronic idiopathic constipation unresponsive to traditional treatment. Pelvic floor abnormalities and transit time should not be the selection criteria for treatment.

Clinicopathologic study of mucosa-associated lymphoid tissue lymphoma in gastroscopic biopsy

AIM: To explore and discuss the clinicopathologic characteristics of mucosa-associated lymphoid tissue (MALT)lymphoma in gastroscopic biopsy specimen. METHODS: A retrospective study of 26 cases of lymphoma diagnosed by gastroscopic biopsy during 1999 to 2001 from gastroscopy files of Xijing Hospital was made. The diagnostic criteria were adopted according to the new classification of non-Hodgkin's lymphoma. RESULTS: Twenty-six cases of primary gastric lymphoma consisting of 15 men and 11 women, aged between 23 to 76 years were recruited from 6 225 cases who Received gastroscopy. All of them were diagnosed by both endoscopic findings and histological examinations. Histologically, 23cases were MALToma (low grade) and 3 cases lymphoblastic lymphoma (high grade). Immunohistochemically, all cases were CD20 positive, while CK and EMA were negative. CONCLUSION: The majority of the cases of primary lowgrade gastric lymphoma have morphologic and clinical features that justify their inclusion in the category of lowgrade lymphoma of mucosa associated lymphoid tissue.

In-situ A1/24Si Functional Graded Materials Prepared by Electromagnetic Separation

Cylinder-like in-situ AI/24Si FGMs were produced by using electromagnetic separating process. Si primary phase reinforced layer with volume fraction as high as 16 pct was formed at the outer region of the cylinder-like samples where the local hardness and wear resistance were enhanced remarkably. Moreover, both of strength and ductility in the inner region provided insurance of reliable strength for this as-cast gradient material. It indicated that general mechanical properties such as good wear resistance at the outer region and good ductility in the central part could be obtained with the optimized redistribution of the Si primary particles under the electromagnetic force.

Determination of interface layer thickness of a pseudo two—phase system by extension of the Debye equation

The Debye equation with slit-smeared small angle x-ray scattering(SAXS) data is extended form an ideal two-phase system to a pseudo two-phase system with the presence of the interface layer,and a simple accurate solution is proposed to determine the average thickness of the interface layer in porous materials.This method is tested by experimental SAXS data,which were measured at 25℃,of organo-modified mesoporous silica prepared by condensation of tetraethoxysiland(TEOS) and methyltriethoxysilane(MTES) using non-ionic neutral surfactant as template under neutral condition.

Fractals of Silica Aggregates

Silica aggregates were prepared by base-catalyzed hydrolysis and condensation of alkoxides in alcohol.Polyethylene glycol(PEG) was used as organic modifier.The sols were characterized using Small Angle X-ray Scattering (SAXS) with synchrotron radiation as X-ray source.The structure evolution during the sol-gel process was determined and described in terms of the fractal geometry.As-produced silica aggregates were found to be mass fractals.The fractl dimensions spanned the regime 2.1-2.6 corresponding to more branched and compact structures.Both RLCA and Eden models dominated the kinetic growth under base-catalyzed condition.

SAXS andalysis of interface in organo—modified mesoporous silica

A small-angle x-ray scattering(SAXS)technique using synchrotron radiation as the x-ray source has been employed to characterize the microstructure of mesoporous silica prepared by one-pot template-directed synthesis methodology.The scattering of pure silica agreed with Porod’s law.the scattering of organomodified mesoporous silica showed a negative deviation from Porod’s law,suggesting that an interfacial layer exists between the pores and silica matrix.It was the organic groups comprising the interface,as shown by ^29Si cross-polarization magic-angle spinning nuclear magnetic resonance imaging (^29Si cp MAS/NMR) and Fourier transform infrared spectroscopy(FTIR),that caused this negative deviation of SAXS intensity from Porod’s law,and the average thichness of the interfacial layer could be deduced from this negative deviation.Copyright 2001 john Wiley and Sons,Ltd.

Determination of Average wall Thickness of Mesoporous silica

Small X-ray Scattering (SAXS) experiment using Synchrotron Radiation as X-ray source was used to determine the average wall thickness of mesoporous silica prepard by condensation of tetraethylorthosilicate(TEOS) using non-ionic alkylpolyethyleneoxide(AEO9) surfactant as templates.The results agreed with that of high-resolution TEM(HRTEM) measurement.

A Genome Sequence of Novel SARS-CoV Isolates: the Genotype, GD-Ins29, Leads to a Hypothesis of Viral Transmission in South China

We report a complete genomic sequence of rare isolates (minor genotype) of the SARS-CoV from SARS patients in Guangdong, China, where the first few cases emerged. The most striking discovery from the isolate is an extra 29-nucleotide sequence located at the nucleotide positions between 27,863 and 27,864 (referred to the complete sequence of BJ01) within an overlapped region composed of BGI-PUP5 (BGI-postulated uncharacterized protein 5) and BGI-PUP6 upstream of the N (nucleocapsid) protein. The discovery of this minor genotype, GD-Ins29, suggests a significant genetic event and differentiates it from the previously reported genotype, the dominant form among all sequenced SARS-CoV isolates. A 17-nt segment of this extra sequence is identical to a segment of the same size in two human mRNA sequences that may interfere with viral genome replication and transcription in the cytosol of the infected cells. It provides a new avenue for the exploration of the virus-host interaction in viral evolution, host pathogenesis, and vaccine development.

The E Protein Is a Multifunctional Membrane Protein of SARS-CoV

The E (envelope) protein is the smallest structural protein in all coronaviruses and is the only viral structural protein in which no variation has been detected. We conducted genome sequencing and phylogenetic analyses of SARS-CoV. Based on genome sequencing, we predicted the E protein is a transmembrane (TM) protein characterized by a TM region with strong hydrophobicity and α-helix conformation. We identified a segment (NH2-_L-Cys-A-Y-Cys-Cys-N_-COOH) in the carboxyl-terminal region of the E protein that appears to form three disulfide bonds with another segment of corresponding cysteines in the carboxyl-terminus of the S (spike) protein. These bonds point to a possible structural association between the E and S proteins. Our phylogenetic analyses of the E protein sequences in all published coronaviruses place SARS-CoV in an independent group in Coronaviridae and suggest a non-human animal origin.

Gene Identification and Expression Analysis of 86,136 Expressed Sequence Tags(EST)from the Rice Genome

Expressed Sequence Tag (EST) analysis has pioneered genome-wide gene discovery and expression profiling. In order to establish a gene expression index in the rice cultivar indica, we sequenced and analyzed 86,136 ESTs from nine rice cDNA libraries from the super hybrid cultivar LYP9 and its parental cultivars. We assembled these ESTs into 13,232 contigs and leave 8,976 singletons. Overall, 7,497 sequences were found similar to the existing sequences in GenBank and 14,711 are novel. These sequences are classified by molecular function, biological process and pathways according to the Gene Ontology. We compared our sequenced ESTs with the publicly available 95,000 ESTs from japonica, and found little sequence variation, despite the large difference between genome sequences. We then assembled the combined 173,000 rice ESTs for further analysis. Using the pooled ESTs, we compared gene expression in metabolism pathway between rice and Arabidopsis according to KEGG. We further profiled gene expression patterns in different tissues, developmental stages, and in a conditional sterile mutant, after checking the libraries are comparable by means of sequence coverage. We also identified some possible library specific genes and a number of enzymes and transcription factors that contribute to rice development.

Complete Genome Sequences of the SARS-CoV: the BJ Group (Isolates BJ01-BJ04)

Beijing has been one of the epicenters attacked most severely by the SARS-CoV (severe acute respiratory syndrome-associated coronavirus) since the first patient was diagnosed in one of the city's hospitals. We now report complete genome sequences of the BJ Group, including four isolates (Isolates BJ01, BJ02, BJ03, and BJ04) of the SARS-CoV.It is remarkable that all members of the BJ Group share a common haplotype, consisting of seven loci that differentiate the group from other isolates published to date. Among 42 substitutions uniquely identified from the BJ group, 32 are non-synonymous changes at the amino acid level. Rooted phylogenetic trees, proposed on the basis of haplotypes and other sequence variations of SARS-CoV isolates from Canada, USA, Singapore, and China, gave rise to different paradigms but positioned the BJ Group, together with the newly discovered GD01 (GD-Ins29) in the same clade, followed by the H-U Group (from Hong Kong to USA) and the H-T Group (from Hong Kong to Toronto), leaving the SP Group (Singapore) more distant. This result appears to suggest a possible transmission path from Guangdong to Beijing/Hong Kong, then to other countries and regions.

The M Protein of SARS-CoV: Basic Structural and Immunological Properties

We studied structural and immunological properties of the SARS-CoV M (membrane) protein, based on comparative analyses of sequence features, phylogenetic investigation, and experimental results. The M protein is predicted to contain a triple-spanning transmembrane (TM) region, a single N-glycosylation site near its N-terminus that is in the exterior of the virion, and a long C-terminal region in the interior. The M protein harbors a higher substitution rate (0.6% correlated to its size) among viral open reading frames (ORFs) from published data. The four substitutions detected in the M protein, which cause non-synonymous changes, can be classified into three types. One of them results in changes of pI (isoelectric point) and charge, affecting antigenicity. The second changes hydrophobicity of the TM region, and the third one relates to hydrophilicity of the interior structure. Phylogenetic tree building based on the variations of the M protein appears to support the non-human origin of SARS-CoV. To investigate its immunogenicity, we synthesized eight oligopeptides covering 69.2% of the entire ORF and screened them by using ELISA (enzyme-linked immunosorbent assay) with sera from SARS patients. The results confirmed our predictions on antigenic sites.

Strong shape-dependence of Morin transition in α-Fe2O3 single-crystalline nanostructures

Single-crystalline hematite （α-Fe2O3） nanorings （short nanotubes） and nanotubes were synthesized by a hydrothermal method. High-resolution transmission electron microscopy and selected-area electron diffraction confirm that the axial directions of both the nanorings and nanotubes are parallel to the crystalline c-axis. Intriguingly, the Morin transition occurs at about 210 K in the short nanotubes with a mean tube length of about 115 nm and a mean outer diameter of about 169 nm. However, it does not occur in the nanotubes with a mean tube length of about 317 nm and a mean outer diameter of about 148 nm. Detailed analysis of magnetization data, X-ray diffraction patterns, and room-temperature M6ssbauer spectra demonstrates that this very strong shape-dependence of Morin transition is intrinsic to hematite. We explain this intriguing shape- dependence quantitatively, in terms of the opposite signs of the surface mag- netic anisotropy constants of the surface planes parallel and perpendicular to the c-axis.

A Statistical Approach Designed for Finding Mathematically Defined Repeats in Shotgun Data and Determining the Length Distribution of Clone-Inserts

The large amount of repeats, especially high copy repeats, in the genomes of higher animals and plants makes whole genome assembly (WGA) quite difficult. In order to solve this problem, we tried to identify repeats and mask them prior to assembly even at the stage of genome survey. It is known that repeats of different copy number have different probabilities of appearance in shotgun data, so based on this principle, we constructed a statistical model and inferred criteria for mathematically defined repeats (MDRs) at different shotgun coverages. According to these criteria, we developed software MDRmasker to identify and mask MDRs in shotgun data. With repeats masked prior to assembly, the speed of assembly was increased with lower error probability. In addition, clone-insert size affects the accuracy of repeat assembly and scaffold construction. We also designed length distribution of clone-inserts using our model. In our simulated genomes of human and rice, the length distribution of repeats is different, so their optimal length distributions of clone-inserts were not the same. Thus with optimal length distribution of clone-inserts, a given genome could be assembled better at lower coverage.