Joint Concurrent Routing and Multi-Pointer Packet Scheduling in IEEE 802.16 Mesh Networks

IEEE 802.16, also known as Worldwide Interoperability for Microwave Access (WiMAX), is a standardization effort carried out by the IEEE to provide last-mile broadband access to end users. The IEEE 802.16 standard supports two medium access control (MAC) modes - a mandatory point to multipoint (PMP) mode and an optional mesh mode. In this paper, we propose an asymmetric interference aware routing algorithm and a new multipointer approach in implementing scheduling algorithms for IEEE 802.16 mesh networks. We modify three different centralized scheduling algorithms, fixed scheduling, ordered scheduling and per-slot scheduling using multipointer approach to allow for spatial reuse (SR) in IEEE 802.16 mesh networks. Simulation results reveal that fixed scheduling with SR provides the best performance

Protein extraction from the stem of Panax ginseng C. A. Meyer: A tissue of lower protein extraction efficiency for proteomic analysis

Ginseng stem, the aerial part of the ginseng is more susceptible to diseases and environmental damages in its long process of growth. Since the molecular mechanism of why ginseng stems are vulnerable remains unclear, the comparison between healthy and pathogen suspicious tissues via proteomics approaches, such as 2-DE, could facilitate the deciphering of the pathogenesis of ginseng and improve ginseng planting industry. A major obstacle for the proteomics study of ginseng stem is the low extraction efficacy of protein due to the properties of its interfering compounds. Here, we tested six different protocols of protein extraction, and identified a protocol that gave us satisfactory yield for 2-DE analysis. The protein extraction was further optimized by chloroform/isoamylol and Tris-saturated phenol extraction that reached the standard of protein purity for 2-DE. Then, using the new extraction protocol, we can efficiently analyze the protein expression patterns of ginseng stem which might provide important information for our understanding of the disease mechanism. Also, our study would lay a foundation for the systematic analysis of the proteomics of ginseng and provide a methodological reference for other similar plant tissues.Key words: Protein extraction, lower protein extraction efficiency, ginsengstem, two-dimensional electrophoresis

High volumetric energy density capacitors based on new electrode material lanthanum nitride

This is the author accepted manuscript. The final version is available from the American Chemical Society via the DOI in this recordLaN is synthesized via calcining La2O3 in NH3 and studied as capacitive material for energy storage. A volumetric capacitance of 951.3 F cm-3 was found in 1 mol dm-3 Na2SO4 using a current density of 1 Ag-1, with less than 1% loss of capacitance being experienced after 5000 cycles. In addition, 87.3% of the initial capacitance remained at a current density of 10 A g-1. LaN exhibits high capacitance that is attributed to subsurface space charge accumulation with a possible electric double-layer capacitor component. A reversible electrode process ensures long cycle life and favorable electrical charge transfer. The assembled LaN symmetrical capacitor showed high volumetric energy densities, facilitating high-duty applications.National Natural Science Foundation of ChinaFoundation for Innovation Groups of Basic Research in Gansu Provinc

Antisense-induced suppression of taxoid 14β- hydroxylase gene expression in transgenic Taxus × media cells

The enzyme taxoid 14β-hydroxylase (14OH) directs a side-route of taxol pathway to 14β-hydroxy taxoids. Suppression of this side-route could increase the production of taxol. To suppress taxoid 14β- hydroxylase gene (14OH) expression in the Taxus × media TM3 cell line, antisense RNA inhibition approach was used in this study. Following the construction of an antisense RNA expression vector of 14OH from Taxus chinensis, the antisense 14OH cDNA (as14OH) was introduced into TM3 cells by Agrobacterium tumefaciens-mediated transformation. Southern blot analysis of hygromycin phosphotransferase gene (HYG) revealed that this selection gene was integrated successfully into the genome of Taxus × media cells. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that the 14OH mRNA level in transgenic cells dropped dramatically, suggesting that the expression of endogenous14OH gene was significantly suppressed by the exogenous as14OH gene. Correspondingly, the total yield of three major C-14 oxygenated taxoids (yunnanxane, taxuyunnanine C, sinenxan C) was markedly reduced in the silenced cell lines when compared with those of the nontransgenic controls. These results indicated that the antisense RNA strategy is a useful tool in suppressing the expression of genes in Taxus and this method could be used to silence other important genes that divert Taxol pathway to side-route metabolites.Key words: Taxus × media, taxoid 14β-hydroxylase, antisense, gene suppression

Preparation and analysis of a new bioorganic metallic material

Biofouling on metal surfaces is one of the main reasons for increased ship drag. Many methods have already been used to reduce or remove it with moderate success. In this study, a synthetic peptide has been utilized to react with 304 stainless steel aiming to generate a bioorganic stainless steel using a facile technique. After the reaction, white matter was found on the surface of the treated stainless steel via SEM, whilst the nontreated stainless steel had none. Elemental analysis confirmed that excessive N existed on the surface of the treated samples using an integrated SEM-EDS instrument, implying the presence of peptides binding on the surface of the bioorganic stainless steel. The FTIR spectra showed amide A and II peaks on the surface of the bioorganic stainless steel suggesting that either the peptides grafted onto the steel surface or the polypeptide composition accumulated on the steel samples. XPS analysis of the treated steel demonstrated that there was nitrogen bonding on the surface and it was a chemical bond via a previously unreported chemical interaction. The treated steel has a markedly increased contact angle (water contact angle of 65.7 ± 4.7° for nontreated steel in comparison to treated, 96.4 ± 2.1°), which supported the observation of the wettability change of the surface, i.e. the decrease of the surface energy value after peptide treatment. The changes of the surface parameters (such as, Sa, Sq, Ssk and Sku) of the treated steel by surface analysis were observed

Prognostic utility of HOXB13 : IL17BR and molecular grade index in early-stage breast cancer patients from the Stockholm trial

Background: A dichotomous index combining two gene expression assays, HOXB13:IL17BR (H:I) and molecular grade index (MGI), was developed to assess risk of recurrence in breast cancer patients. The study objective was to demonstrate the prognostic utility of the combined index in early-stage breast cancer. Methods: In a blinded retrospective analysis of 588 ER-positive tamoxifen-treated and untreated breast cancer patients from the randomized prospective Stockholm trial, H:I and MGI were measured using real-time RT-PCR. Association with patient outcome was evaluated by Kaplan-Meier analysis and Cox proportional hazard regression. A continuous risk index was developed using Cox modeling. Results: The dichotomous H:I+MGI was significantly associated with distant recurrence and breast cancer death. The >50% of tamoxifen-treated patients categorized as low-risk had <3% 10-year distant recurrence risk. A continuous risk model (Breast Cancer Index (BCI)) was developed with the tamoxifen-treated group and the prognostic performance tested in the untreated group was 53% of patients categorized as low-risk with an 8.3% 10-year distant recurrence risk. Conclusion: Retrospective analysis of this randomized, prospective trial cohort validated the prognostic utility of H:I+MGI and was used to develop and test a continuous risk model that enables prediction of distant recurrence risk at the patient level.Original Publication:Piiha-Lotta Jerevall, Xiai-Jun Ma, Hongying Li, Ranelle Salunga, Nicole C. Kesty, Mark G. Erlander, Dennis Sgroi, Birgitta Holmlund, Lambert Skoog, Tommy Fornander, Bo Nordenskjöld and Olle Stål, Prognostic utility of HOXB13:IL17BR and Molecular Grade Index in early-stage breast cancer patients from the Stockholm trial, 2011, British Journal of Cancer, (104), 11, 1762-1769.http://dx.doi.org/10.1038/bjc.2011.145Copyright: Nature Publishing Grouphttp://npg.nature.com

Cancer care in China: A general review

This article is to provide a general overview of cancer in China including the statistics, most common cancers, their epidemiological characteristics and the treatments

Re-evaluating early breast neoplasia

Historically, histomorphological and epidemiological data suggested that atypical ductal hyperplasia and ductal carcinoma in situ are the earliest recognizable neoplastic stages of breast cancer progression. Over the past several years, detailed high-throughput molecular genetic, gene expression and epigenetic analyses have enhanced our understanding of these early neoplastic lesions and have re-shaped our view of human breast cancer progression to include multiple distinct pathways of evolution

Si solid-state quantum dot-based materials for tandem solar cells

The concept of third-generation photovoltaics is to significantly increase device efficiencies whilst still using thin-film processes and abundant non-toxic materials. A strong potential approach is to fabricate tandem cells using thin-film deposition that can optimise collection of energy in a series of cells with decreasing band gap stacked on top of each other. Quantum dot materials, in which Si quantum dots (QDs) are embedded in a dielectric matrix, offer the potential to tune the effective band gap, through quantum confinement, and allow fabrication of optimised tandem solar cell devices in one growth run in a thin-film process. Such cells can be fabricated by sputtering of thin layers of silicon rich oxide sandwiched between a stoichiometric oxide that on annealing crystallise to form Si QDs of uniform and controllable size. For approximately 2-nm diameter QDs, these result in an effective band gap of 1.8 eV. Introduction of phosphorous or boron during the growth of the multilayers results in doping and a rectifying junction, which demonstrates photovoltaic behaviour with an open circuit voltage (VOC) of almost 500 mV. However, the doping behaviour of P and B in these QD materials is not well understood. A modified modulation doping model for the doping mechanisms in these materials is discussed which relies on doping of a sub-oxide region around the Si QDs