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To explore the feasibility of subserosal injection of carbon nanoparticle via venous infusion needle to label lymph node and its application value in laparoscopic radical gastrectomy.Forty patients with gastric cancer were randomly divided into two groups (carbon nanoparticle group and control group). Subserosal injection of carbon nanoparticle around the tumor was performed via venous infusion needle laparoscopically at the beginning of surgery in carbon nanoparticles group, while the patients routinely underwent laparoscopic radical gastrectomy in control group. Results of harvested lymph nodes were compared between the two groups. The perioperative complications and the side effect of carbon nanoparticle were also evaluated.The average number of harvested lymph node in carbon nanoparticle group (31.7±7.6) was significantly higher than that in control group (19.8±6.1, P0.05). The proportion of harvested small node (5 mm) in carbon nanoparticles group(61.0%) was higher than that in control group(43.3%, P0.01). The mean harvest time in carbon nanoparticle group [(23.5±4.8) min] was shorter than that in control group [(32.6±5.5) min, P0.05]. The rate of black-dyed harvested lymph node was 61.9% and the metastasis rate of black-dyed lymph node was 23.0% in carbon nanoparticle group, which were significantly higher than those without black-dyed(6.2%, P0.05) and those in control group (15.7%, P0.05). The operative time and perioperative complications were not significantly different between the two groups, and no serious side effect caused by carbon nanoparticle was observed.Subserosal injection of carbon nanoparticle via venous infusion needle to label lymph nodes during laparoscopic radical gastrectomy is safe and feasible. It can increase the number of harvested lymph node, especially the small node.

Supercapacitors are important energy storage technologies in fields such as fuel-efficient transport and renewable energy. State-of-the-art supercapacitors are capable of supplanting conventional batteries in real applications, and supercapacitors with novel features and functionalities have been sought for years. Herein, we report the realization of a new concept, a smart supercapacitor, which functions as a normal supercapacitor in energy storage and also communicates the level of stored energy through multiple-stage pattern indications integrated into the device. The metal-oxide W18O49 and polyaniline constitute the pattern and background, respectively. Both materials possess excellent electrochemical and electrochromic behaviors and operate in different potential windows, -0.5-0 V (W18O49) and 0-0.8 V (polyaniline). The intricate cooperation of the two materials enables the supercapacitor to work in a widened, 1.3 V window while displaying variations in color schemes depending on the level of energy storage. We believe that our success in integrating this new functionality into a supercapacitor may open the door to significant opportunities in the development of future supercapacitors with imaginative and humanization features.

The capability of imaging and detecting single DNA molecules is critical in the study, analysis, and applications of DNA. Fluorescence imaging is a widely used method, but it suffers from blinking and photobleaching, and fluorescence tags may block or affect binding sites on DNA. We report on label-free imaging of single DNA molecules with a differential plasmonic imaging technique. The technique produces high contrast images due to the scattering of surface plasmonic waves by the molecules and the removal of background noises and interference patterns, allowing for quantitative analysis of individual DNA molecules. Simulation of the images based on a scattering model shows good agreement with the experiment. We further demonstrate optical mapping of single DNA molecules.

Three novel imidazole[4,5-f][1,10]phenanthroline-based oxovanadium complexes [VO(hntdtsc)(HPIP)] (1) (hntdtsc = 2-hydroxyl-1-naphthaldehyde thiosemicarbazone, HPIP = 2-(2-hydroxylphenyl)imidazole[4,5-f][1,10]phenanthroline), [VO(hntdtsc)(m-HPIP)] (2) (m-HPIP = 2-(3-hydroxylphenyl)imidazole[4,5-f][1,10]phenanthroline), [VO(hntdtsc)(p-HPIP) (3) (p-HPIP = 2-(4-hydroxylphenyl)imidazole[4,5-f][1,10]phenanthroline), have been synthesized and characterized by elemental analyses and spectroscopic techniques. Their DNA-binding properties with calf-thymus DNA (CT-DNA) were studied by various methods. The cytotoxicity of these three complexes was evaluated by 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The electronic spectral results reveal that three complexes can bind to CT-DNA by intercalation mode. The electrophoresis studies also show that they can efficiently cleave pBR322 DNA. The in vitro antiproliferative activity of complex 1 against human CaSki, SiHa, K562, HepG2, EC9706 and EC109 cell lines is proved to be more effective than both 2 and 3.

This work describes an algorithm that uses the Heidemann and Khalil (1980, A.I.Ch.E. J., 26, 769}779) critical point criteria and a homotopy continuation technique for calculating critical loci in binary mixtures. This approach is able to track smoothly transition from G/L critical points to L/L critical points without the need of changing initial estimates. Such transitions marked by the existence of a turning point in the critical locus are commonly found in type III and IV mixtures. The tangent plane global stability tests are included to locate UCEPs and LCEPs which are intersections of the critical locus and the LLG line. The continuation method is as e$cient as a gradient-based approach like Heidemann and Khalil’s method and as robust as the Hicks and Young’s grid-search approach. It also provides physical insight to the change in phase behavior as the composition and the equation of states parameters change. ( 1999 Elsevier Science Ltd. All rights reserved.

A method for the determination of a-1-fetoprotein (AFP) in human serum by using a horseradish peroxidase (HRP) label in an enzymelinked immunosorbent assay (ELISA) is proposed. The method is based on the electrochemical determination of enzymatic reaction product with differential pulse voltammetry at a gold disk electrode. The assay consists of two successive steps. The first step is a conventional HRP-mediated ELISA for the formation of electroactive 2,2 0 -diaminoazobenzene by means of the o-phenylenediamine2H2O22HRP system. At the second step, 2,2 0 -diaminoazobenzene exhibits a sensitive voltammetric response atˇ0.19 V in pH 2.0 PBS. The peak current is proportional to the concentration of AFP in the range of 0.5‐400 ngymL (Ra 0.9993) under optimum conditions. The sensitivity of this method is higher than that of the traditional spectrophotometric ELISA procedure. The proposed method has been applied to the clinical determination of AFP in human serum with satisfactory precision and accuracy.

The three-dimensional (3D) expanded graphite-carbon nanotube (EG-CNT) nanocomposite was prepared by in situ growing CNTs between graphite layers in thermally expanded graphite. The morphology and microstructure of the nanocomoposite were characterized by SEM, TEM, Raman and XRD analyses, respectively. The results show that intimately contacted EG-CNT interface has been formed within the multilayered composite architecture. Furthermore, paraffin was used as a filler to occupy the free spaces of the EG-CNT nanocomposite for thermal application. The as-obtained composite structure is inclined to conduct heat isotropically and shows a thermal conductivity higher than 10 W/m·K at a paraffin loading of 49 wt.%, which indicates that EG-CNT nanocomposite could be promising candidates for thermal management in electronic package.

To identify the risk factors for apical node metastasis in colorectal cancer (CRC) patients who underwent laparoscopic radical resection with D3 lymphadenectomy. The subjects were 578 consecutive patients who underwent laparoscopic radical resection with D3 lymphadenectomy for CRC between February, 2003 and December, 2009. The Cox proportional regression model was used to evaluate the association between apical node metastasis and survival and the logistic regression model was used to identify the risk factors for apical node metastasis. Thirty patients (5.2 %) had apical node metastasis, which was an independent risk factor for poor disease-free survival [hazard ratio (HR) = 3.02, P = 0.019]. Multivariate logistic regression analysis revealed that poor differentiation [odds ratio (OR) = 4.58, P

The stress corrosion behaviors of submerged arc welding X80 pipe, widely used in the West-East Gas Project II, are studied in five typical soil simulation solutions: (1) made from brown desert soil collected from Hami of Xinjiang Province, (2) meadow solonchak collected from Yumen of Gansu Province, (3) cinnamon soil collected from Yichuan of Henan Province, (4) yellow-brown soil collected from Wuhan of Hubei Province, and (5) red oil collected from Zhangshu of Jiangxi Province, respectively). The results showed a certain degree of stress corrosion susceptibility of X80 pipeline steel studied in those soil simulation solutions, but they were not serious. The stress corrosion susceptibility of the X80 pipeline steel gradually decreases from Yumen (meadow solonchak) soil, Yichuan (cinnamon) soil, Wuhan (yellow-brown) soil, Hami (brown desert) soil and Zhangshu (red) soil. Serious pitting occurred on the specimen in red soil simulation solution. The corrosion behavior of X80 pipeline steel in the other four kinds of simulation solutions was governed by general corrosion, although there were a few pitting occurrences on local positions.

A systematic investigation of the effect of material inhomogeneity on pipe buckling is presented in this paper. The material properties of the pipe were obtained by a series of tensile tests. Numerical simulations were carried out to evaluate the effect of material inhomogeneity on pipe buckling. Post-buckling behavior was also simulated. This paper also explains the mechanism of cracking.The authors show how pipe buckling can be caused by weakened sections, and how both internal pressure and the ratio of diameter to thickness can significantly affect pipe buckling.

Few analytical models have been proposed to evaluate the hybrid of the basic and the RTS/CTS access mechanisms up to now. The main reason is that it is very difficult to study a scheme with variable packet length. In this letter, we propose a model to evaluate the saturation throughput performance of the hybrid access mechanism, assuming that the packet lengths are sampled from a general distribution function f(x).

A new amperometric electrode for the assay of lactate dehydrogenase (LDH) is prepared by modifying a nanometer—sized microband gold electrode with nickel hexacyanoferrate. The amperometric determination bases on electrochemically detecting NADH produced by the enzymatic reaction of lactate with NAD+ under the catalysis of LDH. The modified electrode can sensitively detect LDH at +0.55V vs. SCE with a linear response in the range of 10U / mL to 350U / mL under optimum conditions.

A more flexible grounding resistance calculation method, based on finite element analysis (FEA) method, is suggested, which is especially suitable for optimization cathodic protection (CP) ground-bed arrangement. As compared with traditional grounding resistance evaluation method, which is only suitable for the case of each anode rod in a straight line, the FEA method can calculate grounding resistance of ground-bed at any arrangement. Moreover, a realistic soil resistance rate, usually varying with depth, can be included in calculation model. The detailed steps for this method can be summarized as follow: building a 3D geometric model according to general design, meshing the geometric model, setting reasonable boundary conditions, solving and post-solving the grounding resistance with ohmic law. To further explain this procedure, a realistic CP ground-bed displacing project is presented, which includes displacing the original CP ground-bed firstly and re-designing a new ground-bed within a limited area (5m×30m). A new CP ground-bed design, compared with traditional design, 2×7, 14 anode rods dispersed in two parallel groups, are calculated firstly. The results show that this design can not meet the grounding resistance requirement. Another 4 designs, with anode rods arranged as 2×6, 2×8, 2×9, 3×6 are calculated respectively. Finally, the design 2×8 is recommended from the view of economy and practicability.

An indoor simulation equipment for DC interference corrosion was established to evaluate the relationship among outflowing current density, soil types and corrosion behavior of 16MnR steel. The influence of testing mode for that equipment was also investigated. The results show that: (1) the mode of "constant current cathodic protection & constant DC current interference" was the best operating mode of the indoor simulation equipment; (2) the corrosion behavior of DC stray interference was dominated by the DC interference intensity, while the influence of soil which hardens performance on corrosion behavior was significant; and (3) the corrosion rate was proportional to the outflowing DC current density of specimen, but the characteristics of localized corrosion was more obvious with the increase of the corrosivity of soil.

Due to rapid development of HVAC transmission lines, AC electric railways and oil and gas pipelines, these lines will inevitably cross or lie parallel to each other. At these positions, pipelines will be subject to serious interferences. In most situations, only the results of an interference are detectable, with no clue as to what caused the problem. This paper presents a new method designed to solve AC interference. When the interference source cannot be determined, AC voltages of buried pipelines are first measured and the AC interference is simulated. Furthermore, a mitigation method is built using computer software. After mitigation devices are installed on the pipeline, AC voltages are simulated once more and compared with field-measured values. The result shows that the simulated AC interference and the subsequent mitigation method built with computer software are more efficient.

In a real wireless channel, both a channel bit error and a collision between competition stations can cause a data frame loss. Moreover, DCF always assumes that a data frame loss is due to the collision and the contention window will double in next transmission. In fact, we think that the contention window shall be difference between channel bit error and collision. In this paper, we propose a ideal mechanism LD-DCF which can completely differentiate between the two reasons of a data frame loss. An analytical model is given to demonstrate the efficiency of LD-DCF. NS-2 simulation is also used to validate the LD-DCF. By the theoretical and simulation results, the LD-DCF can improve the throughput significantly, especial for the high channel bit error and low contending stations (i.e. the low network traffic).

DCF adopts a binary backoff procedure in order to avoid the further collision. In a real wireless channel, both a channel bit error and a collision can cause a data frame loss. However, DCF always assumes that a data frame loss is due to the collision. In fact, a channel bit error should not cause the backoff window double. In this paper, we propose a Collision Aware (CA) DCF to differentiate between channel error and collision. The CA-DCF introduces a CA frame which is so small size that it is loss only due to collision. Through theoretical analysis, an optimal backoff window is deduced and the CA-DCF adopts the fixed optimal window as the backoff window. NS-2 simulation results show that the CA-DCF is an effective scheme. Keywords-IEEE 802.11, CSMA/CA, DCF, Collision Aware

Two new series of 15-membered macrocyclic peptidomimetics, in which the P1 and P3 residues of the peptide backbone are linked by a bridge containing a 1,4-disubstituted 1H-imidazole, are reported. The structure with an aldehyde at the C-terminus and the imidazole at P3, i.e., 4c, shows significant inhibitory activity against calpain 2, with an IC(50) value of 238 nM. The macrocyclic aldehyde with the imidazole at the alternative P1 position, i.e., 5c, is significantly less active. The relative activities are linked to the ability of the component macrocycles to mimic a β-strand geometry that is known to favor active-site binding. This ability is defined by conformational searches and docking studies with calpain.

In IEEE 802.16e (WiMAX), each data burst consists of multiple MPDUs. The MPDUs of one data burst are distinguished from each other according to the generic MAC header (GMH). The GMH contains the length information of MPDU. If the GMH is damaged, it doesn’t know what’s end of the MPDU. As a result, the damaged MPDU and successive MPDUs in the data burst shall be discarded even if the successive MPDUs are correct received. In this paper, we point out the cursory discarding and propose a recovering scheme to improve the network bandwidth. KeywordsIEEE 802.16e, WiMAX, HCS, CRC

This article provides a saturation throughput analysis of IEEE 802.11n when Block-ACK is adopted. In contrast to the previous models, our model gives more accurate results owing to taking into account the freezing of backoff counter and anomalous slots. Simulation results show the accuracy of our model. Keywords-IEEE 802.11n, CSMA/CA, Block-ACK

Stray current interference may cause pipeline corrosion, which will result in premature failure of pipeline and potential safety problem to the persons who would touch the pipe during the work. The results of systematic field survey of the AC interference on an oil products pipeline showed that the range of quasi-stable AC interference was more than 20 km. Moreover, the risk of two separate pipeline sections among them was medium or worse. The relationship among corrosion rate, AC interference voltage, and AC interference current density was summarized after on-site tests. Finally, some mitigation suggestions were proposed.

We have developed an air-stable soluble polyethylene glycol bound ruthenium catalyst which performs efficient ring-closing metathesis in organic solvents as well as in aqueous media.

A sensitive method for the determination of nanomolar concentrations of guanine in a medium of 0.02 M NaHCO 3 -0.06 M Na 2 SO 4 by differential pulse adsorption cathodic stripping voltammetry has been developed. The limit of detection is 3 × 10 −10 M guanine. In the presence of 10-fold guanosine (at a concentration of 2 × 10 −7 M ) ca. 2 × 10 −9 M guanine can be detected. By means of cyclic voltammetry and other electrochemical methods, a new viewpoint on the mechanism of the overall electrode process for guanine at a hanging mercury drop electrode in the potential range of −1.0 to +0.2 V (vs SCE), including two separate steps, has been proposed.

Genetic variations in the gene XPC may be associated with increased risk for gallbladder cancer (GBC). In this study, we detected two non-synonymous polymorphisms in XPC (Ala499Val and Lys939Gln) in 334 cases of GBC and 329 subjects of hospital-based age- and sex frequency-matched controls in China using a polymerase chain reaction-restriction fragment length polymorphism assay. Allelic association analysis for the two single-nucleotide polymorphisms (SNPs) showed that the risk allele T of Ala499Val was significantly associated with GBC [odds ratio (OR)=1.40, 95% confidence interval (CI): 1.11-1.76, P=0.005), with a population attributive risk of 5.3%. Logistic regression analysis revealed that Ala499Val CT heterozygote (OR=1.56, 95% CI: 1.13-2.14, P=0.002) and TT homozygote (OR=1.93, 95% CI: 1.04-3.55, P=0.048) had a significantly increased risk compared with CC homozygotes. Genetic analysis suggested that either the SNPs directly exert an effect or the linked functional gene impact of the disease trait likely follows an additive or dominant model. Gene interaction analysis demonstrated that the effects of XPC diplotypes (defined as the number of risk genotypes at the two SNP loci) were highly dependent on gallstone. The data from this case-control study indicated that XPC exonic variants contributed to the risk of GBC in this Chinese population.

Based on the invasive plasmid antigen H gene (ipaH) of S. dysenteriae, one pair of specific primers was designed for PCR assays in this study. The concentrations of dNTP, Mg2+ and primer, dosage of Taq DNA polymerase, annealing temperature and circulating parameter in the PCR amplification system were optimized. In this way, a rapid and stable method of PCR assay for the detection of S. dysenteriae was established. The specificity and sensitivity of PCR were also analyzed. The detection limits of pure culture and genomic DNA in the PCR assay were 1.06 x 10(2) cfu/ml and 106.34 pg/PCR system, respectively. The detection limit for S. dysenteriae in artificially contaminated food samples was 3.21 x 10(4) cfu/ml. These results indicated that the PCR method for S. dysenteriae detection was simple, rapid, high in specificity and sensitivity and suitable for the detection of pathogens in foods caused by Shigella dysenteriae.

The surface potential distribution of buried X80 steel under cathodic protection was calculated by finite element method. After comparing the results of simulation and experiment, the advantages and disadvantages of the numerical simulation method used in the present paper were discussed.

A rapid method for the analysis of the main components of the total glycosides of Ranunculus japonicus (TGOR) was developed using ultra-performance liquid chromatography with quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS). The separation analysis was performed on a Waters Acquity UPLC system and the accurate mass of molecules and their fragment ions were determined by Q-TOF MS. Twenty compounds, including lactone glycosides, flavonoid glycosides and flavonoid aglycones, were identified and tentatively deduced on the basis of their elemental compositions, MS/MS data and relevant literature. The results demonstrated that lactone glycosides and flavonoids were the main constituents of TGOR. Furthermore, an effective and rapid pattern was established allowing for the comprehensive and systematic characterization of the complex samples.

To study the anticancer activities of curcumin on human hepatocarcinoma cell line Sk-hep-1 and its related molecular mechanism which has not been elucidated. In the present study,we showed that curcumin inhibited proliferation of Sk-hep-1 cells in a dose-dependent manner through MTF assay. The effect of curcumin on apoptosis in Sk-hep-1 cells was investigated by DAPI staining and the various apoptosis was observed in hepatocarcinoma cell lines Sk-hep-1, HepG2 and Hep3B, but not in normal liver cell line Chang's liver with curcumin treatment. Cell cycle analysis results showed that curcumin treatment resulted in dramatic accumulation of Sk-hep-1 cells at the G0/G1 or G2/M phase. The effect of curcumin on the expression of anti-apoptosis genes (Survivin and BCl-xL) and drug resistance genes (DRG2 and MDR1) was studied by reverse transcription-polymerase chain reaction (RT-PCR). The expression of MDR1 mRNA was significantly decreased in Sk-hep-1 cells treated with curcumin, while no alterations in the amount of DRG2 and anti-apoptosis genes' mRNA levels were found. These results indicate that curcumin is able to inhibit proliferation and induce apoptosis in Sk-hep-1 cells and it may cause by down-regulating the expression of MDR1 mRNA.

In order to achieve safety and reliability of long-distance gas transmission pipeline installed in seismic region while obtaining economical benefit by reducing material and construction cost, it is essential to apply the high-strength linepipes with sufficient strain capacity against buckling and weld fracture by seismic ground movement. At the same time, it is quite important to develop appropriate material requirement for strain capacity depending on the pipe dimension and strain demand of the region where the pipeline is installed. Grade X80 heavy gauge linepipes with excellent deformability were mass produced by applying advanced plate manufacturing technologies. These linepipes exhibit low Y/T and high uniform elongation in the longitudinal direction even after pipe coating. Strain capacity of the pipe against bending deformation with internal pressure was verified by conducting full scale pipe bending testing. In this paper, production results of high strain X80 linepipes for the application in long-distance pipelines in seismic region and full scale pipe bending and hydraulic burst test results were introduced.Copyright © 2010 by ASME

We report the synthesis of macrocycles 1-6 via ring closing metathesis of dienes 7-12. Addition of chlorodicyclohexylborane to thermal and microwave assisted RCM of dienes 8 and 9 markedly improves the yield. The geometric isomers of macrocycles 1-3 and 5 have been assigned using X-ray crystallography and NMR.

With the sharply rising demand of oil and gas, the pipeline industry has been experiencing a rapid development in recent years. Pipelines in the areas of ground movement from slope instability, seismic sideslip, loess collapse, mining subsidence, frost heave and thaw settlement in discontinuous permafrost can experience displacement-controlled plastic strain. The current paper describes the application of strain-based design of pipelines and introduces relevant codes, standards, and criteria of other countries. Some major issues in strain-based design such as geologic conditions, strain limits, mechanical performance, etc., are mentioned. The prospect of strain-based design of pipelines is discussed with reference to the geologic conditions and the state of the pipeline industry. Finally the requirements on parameters of line pipe materials, including yield stress, yield and tensile strength ratio, stress ratio, weld mismatch, anisotropy etc., and their influence on strain-based design are discussed.Copyright © 2009 by ASME

To investigate the impact of phenotypic knockout of CXCR4 on Molt-4 cells via intrakine technology,the C-terminal alpha-helix gene SDF-1alpha/54/KDEL of human stromal cell-derived Faceor-1 deletion is fused to a retention signal 4-peptide -KDEL that retains the newly synthesized receptor within the Molt-4 cells endoplasimc reticulum. Subsequently, PCR is used to amplify the target gene SDF-1alpha/54/ KDEL from the constructed plasmid SDF-WT-Gly x 4-Dec/PET-30a(+) at its C-terminal and subclone it into eukaryotic expression vectors pEGFP-C3 for generating recombinant vector cells by lipEGFP-C3/SDF-1alpha/54/KDEL, and then have it sequenced. After the transfection of recombinant plasmids into COS-7 posome, SDF-1alpha/54/KDEL protein is confirmed with Western blot. The recombinant plasmids pEGFP-C3/SDF-1alpha/54/KDEL are isolated and transiently transfected in Molt-4 cells by electroporation. Flow cytometric analysis shows a dramatic reduction of CXCR4 expression on Molt-4 cells. The conclusion is that SDF-1alpha/54/KDEL could assume a role in the phenotypic knockout of CXCR4, and the findings suggest that the inhibiting effect of SDF-1alpha/54 against CXCR4 is not influenced by the deletion of SDF-1alpha helix at the C terminal.

The 2nd West-East Pipeline Project which are building now is the longest of X80 gas pipeline in China even in the world. The geological conditions along it are very complicate. Both stress-base and Strain-based design are all used in the pipeline design. Strain-based design are considered when the pipeline shall via seismic activities, fault crossing and other geological disaster area where ground moving may happen. The pipe which will be used in this kind of special area shall have some special properties besides the properties requirement of the ordinary line pipe. So Tubular Goods Research Center of China National Petroleum Corporation drafted “the Supplementary Technical Specification of High Strain LSAW Line Pipe for the 2nd West-East Pipeline Project”. In this specification, the strain capacity of current X80 line pipe and the testing methods for the mechanical properties are considered. In the mean time, the risk of aging when the pipes are coated is also be noted, and the coating temperature is specified in the specification. Certainly, besides the deformability of the pipe, strain-based design also needs more measures from pipeline construction, girth welding, etc. to ensure the pipeline can endure certain deformation. This paper introduced the general situation of the 2nd West-East Pipeline Project, and several key issues in the specification of high strain line pipe used in strain-based designed districts. At the end of the paper, the mechanical properties and the deformability of X80 pipe which are possible to be manufactured and used in this gas line are be presented.Copyright © 2008 by ASME

The use of strain based design in pipeline technology has been widely discussed during the last decade for pipelines in harsh environment. In such cases pipelines should be designed based on strain criterion. Strain based design poses a number of challenges, particularly on pipe size and material properties. This paper presents preliminary studies on prediction of buckling strain and buckling mode for X80 high-strain line pipe by finite element methods based on full-scale test. The effects of several parameters such as internal pressure, material properties pipe size and geometric imperfection, were investigated to predict the critical strain for 48″ diameter line pipe under compression and pure bending with 12MPa internal pressure. Material parameters of a specification for high strain line pipe were analyzed to promote its application in the 2nd West-East pipeline of China National Petroleum Corporation.Copyright © 2008 by ASME

The chemokine SDF-1 (CXCL12) and its receptor, CXCR4, have been implicated in organ-specific metastases of several malignancies. CXCR4 expression has recently been characterized in many cancer cell types and is thought to play a pivotal role in directing the migration of metastasizing tumor cells to SDF-1-rich tissues. SDF-1, which is highly expressed in the organs where breast cancers preferentially metastasize, has been shown to promote cancer cell migration. The tumor cells use chemotaxis which occurred between CXCR4 and its ligand SDF-1 to direct migration from their primary sites via the circulation to the preferential sites of metastases, and further studies on the mechanism involved in a variety of cellular signaling pathways are beneficial to tumor therapy.

CXC chemokine receptor 4 (CXCR4) is a cell surface receptor that has been reported to mediate the metastasis of many solid tumors including ovarian, breast, lung and prostate. The over-expression of the epidermal growth factor receptor (EGFR) is associated with the majority of ovarian cancer and has been implicated in the process of malignant transformation by promoting cell proliferation, survival, and motility. In this research, the result first showed that epidermis growth factor (EGF) enhanced the expression of CXCR4 and the migration of ovarian cancer cells, moreover, both stromal cell derived factor-1α (SDF-1α) and EGF-induced high matrix metallopeptidase 9 (MMP9) expressions. Molecular analysis indicated that augmented CXCR4 and MMP9 expression was regulated by phosphatidylinositol-3-kinase(PI3K)/Akt signal transduction pathway. These results suggested a possible important “cross-talk” between CXCR4 and EGFR intracellular pathways that might link signals of tumor deteriorated and provided a plausible explanation for the poor overall survival rate of patients whose co-expression of CXCR4 and EGFR was detected in their tissue sections. It enlightened that, compared to the respective inhibition of the EGFR or CXCR4 signaling, the simultaneous inhibition of them might be a more useful therapeutic strategy of cancer.

Decorin (DCN) is a member of the small leucine-rich proteoglycan gene family. Many studies indicated that DCN inhibited fibrosis and scar-formation by neutralization of TGF-P and interfering the binding of TGF-beta with its receptor, which induced ectopic deposition of extracellular matrix. Additionally, DCN can prevent the proliferation and metastasis of tumor cells by activating EGFR/MAPK/p21 signal pathway and inhibiting the cell proliferation pathway mediated by EGF-EGFR. It is suggested that the recombinant DCN had potential pharmaceutical potency in treatment of chronic fibrosis and neoplasm for its critical biological activities and low immunogenicity.

This paper proposes a method to form a Bluetooth scatternet under the conference scenario. The principles and formulas for calculating network topologies are discussed in detail. The method is proved by implementation using commercially available Bluetooth devices. The scatternet topology can be star, mesh, ring and linked line, which is controlled by changing parameters like the number of maximum slaves in a piconet, the number of maximum piconets that a gateway Bluetooth device can participate, and whether loops are needed in the resulting scatternet. In this paper, we also present a lot of testing results from forming the real scatternet.

This paper proposes a new authentication scheme for accessing contents, services and applications in both mobile device and Internet. A user first divide all the contents, services and applications in both mobile device and the Internet into four groups according to their importance: extremely confidential group (ECG) has security level SL=1, very confidential group (VCG) has SL=2, confidential group (CG) with SL=3 and free accessible group (FAG) with SL=4. If it is Internet content or service or application, the pair of username and password necessary for accessing it is put into the group. In order to access the items in the four groups, four authenticating methods are defined, which generates four active usage levels (AUL). Fingerprint plus password1 authentication generates AUL=1, which grants the right to access all four groups. Fingerprint alone generate AUL=2, which grants the right to access groups of VCG, CG and FAG. Password2 authenticating generates AUL=3, which grants right to access CG and FAG. Null authentication generates AUL=4, which is the default AUL and can only access items in FAG. Once an AUL is generated, user can not only access corresponding groups of information stored in the device but also use that mobile device to access corresponding groups of her/his Web accounts seamlessly without memorizing usernames and passwords. Whenever the user wants to access information stored in the mobile devices, or Web accounts provided by a third party, the security middleware obtains SL required to access them, compares the SL with the AUL. If the AUL is equal to or higher than the SL, the access is granted seamlessly and transparently to the user; otherwise, it asks to authenticate again to gain higher AUL, or the access is denied. After the access right to a device is granted, the user can at any time reset the AUL to 4, or the AUL can be set to 4 automatically after a predefined idle period.

A strategy to detect P-glycoprotein (P-gp) on cell membrane and quantify the cell number using electrochemical immunoassay was developed by effective surface immunoreactions and immobilization of cells on a highly hydrophilic interface, which was constructed by adsorption of colloidal gold nanoparticles on a methoxysilyl-terminated (Mos) butyrylchitosan modified glassy carbon electrode (Au-CS/GCE). Atomic force microscopy studies proved that the nanoparticles adsorbed on Mos-butyrylchitosan were efficient in preventing the cell leakage and retaining the activity of immobilized living K562/ADM leukemic cells. The incubation with P-gp monoclonal antibody and then the secondary alkaline phosphatase (AP) conjugated antibody introduced AP onto the K562/ADM cell immobilized on Au-CS/GCE. The bound AP led to an amperometric response of 1-naphthyl phosphate. Under optimal conditions the response was proportional to the logarithm of cell concentration in the range from 5.0 x 10(4) to 1.0 x 10(7) cells mL(-)(1) with a detection limit of 1.0 x 10(4) cells mL(-)(1). The results were comparable to flow cytometric analysis of P-gp expression. This proposed method was practical, convenient, and significant in the clinic and cytobiology.

The Dly-ACK scheme in IEEE 802.15.3 is designed to reduce the overhead of the ACK and improve the channel utilization. However, the way to use the Dly-ACK is open for implementation. In this paper, we first investigate the problems of applying the fixed Dly-ACK scheme to the TCP stream and show that the TCP performance is rather poor. Then, we propose two enhancement mechanisms for TCP with Dly-ACK over the 802.15.3 system. The first one is to request the Dly-ACK frame adaptively or change the burst size of Dly-ACK according to the queue size. The second is a retransmission counter to enable the destination DEV to deliver the packets to the upper layer timeously and in orderly fashion. Simulation results show that, with our enhancements, the TCP throughput can be improved more than 40% compared with the conventional Imm-ACK. We also investigate the impacts of some important system parameters such as the buffer size on the TCP performance. Some guidelines for the Dly-ACK design are given. Finally, it is worth pointing out that our enhancements are compatible with the standard.

In this paper, we present some observations and analysis on Bluetooth PAN's performance degradation in multi hop network based on our experiments. We highlight a situation in which control packets can be received properly but not data packets, as well as its effects on scatternet performance. Based on our analysis, we propose a cross-layer optimized routing protocol for Bluetooth (CORB), which outperforms AODV based routing protocols. CORB is a QoS-extended AODV routing protocol that is optimized for Bluetooth MAC. It has two unique characteristics. First, it uses a new load metric (LM) in QoS routing protocol instead of the number of hops as in conventional best effort routing. LM reflects nodes' link bandwidth with respect to Bluetooth nodes' role in the scatternet. This helps the CORB to bypass heavily the loaded nodes, and find routes with larger bandwidth. Second, LM and some MAC layer parameters are dynamically adjusted in response to the changes in radio conditions. These two characteristics of CORB contribute to its improved stability, and rapid response to changing radio conditions

Single and multijunction nanowires with diameters of 10-40 nm were synthesized by an electrically assisted sonochemical method in aqueous solution at room temperature. By properly controlling the reaction conditions and reactants, this method opens a new strategy towards the fabrication of one-dimensional superlattices in nanowires under ambient conditions. Such a chemical approach provides a promising and simple way to synthesize high-performance building blocks for device applications.

This paper focuses on the impact of topology on Bluetooth personal area network. We first present some observations on performance degradations of Bluetooth PAN due to network topologies, and then analyze its reason. Based on our analysis, we propose a flexible scatternet formation algorithm under conference scenario for multi-hop communication. By using proposed method, scatternet can be formed flexibly with different topologies under a controlled way. To utilize topology information in multi-hop communication, we propose a new link metric Load Metric(LM) information in multi-hop communication, we propose a new link metric Load Metric(LM) instead of number of hops. LM is derived from estimation of nodes’ link bandwidth, which reflects different roles of nodes in Bluetooth scatternet. This proposal helps routing protocol to bypass heavily loaded nodes, and find route with larger bandwidth. We present some experimental results based on implementation, which prove the effectiveness of our protocols.

Compressed data are sensitive to any errors because they will spread on decompression. In order to overcome this in the case of arithmetic codes, some variable-to-fixed length (VF) arithmetic codes with error detecting capabilities were proposed by Cho and Kohno (1998), but no paper, up to now, has discussed the joint coding of data compression and error correction. This paper proposes an l-burst error recovery method for VF arithmetic codes. It divides the compressed data into fixed length words and inserts the internal states of the decompressor as well as the check parts of the interleaved parity code and the cyclic code into each word.

In this paper, performances when go-back-N (GBN) and selective repeat (SR) ARQ are applied in high speed ATM networks are studied. They can be used in regenerators or completely from transmitter to end receiver. Details of cell format, format of acknowledgment cell, CRC code and analytical results of throughputs, traffic increments as well as buffer requirements of the two proposed ARQs are given in the paper. A method of estimating the error detecting capability is developed. Finally, The operations of transmitter and receiver are designed and simulated. Analytical and simulation results reveal that high throughput can be achieved and buffer size is acceptable.