1,513 research outputs found

    Cervical lymph node metastatic patterns of squamous carcinomas in the upper aerodigestive tract

    Get PDF
    The radical neck dissection specimens of 384 ethnically Chinese patients with different primary squamous carcinomas in the head and neck region were studied. Over 50 per cent of the specimens showed metastatic disease at one level in the neck. For oral cavity carcinoma, the levels of metastasis frequently involved were I, II and III while for carcinoma of the oropharynx, hypopharynx and larynx, the levels were II, III and IV. Extracapsular spread was present in 112/384 of patients (29 per cent) and this increased with advancing N-stages. Based on these findings, different selective neck dissections could be used for patients harbouring different primary head and neck carcinomas with limited neck disease.published_or_final_versio

    Fe(II)-EDTA chelate-induced aromatic hydroxylation of terephthalate as a new method for the evaluation of hydroxyl radical-scavenging ability

    Get PDF
    The investigation of Fe(ii)-EDTA chelate-induced aromatic hydroxylation of terephthalate in pH 7.4 phosphate buffer solution and a new method for the evaluation of hydroxyl radical-scavenging ability are reported. The method is based on attack of the hydroxyl radical on the terephthalate to produce highly fluorescent 2-hydroxyterephthalate, which is detected fluorimetrically. The formation of hydroxyl radical is believed to be the result of the reduction of molecular oxygen by Fe(ii)-EDTA to form superoxide radical, which in turn dismutates to hydrogen peroxide, and then Fe(ii)-EDTA catalyzes the decomposition of hydrogen peroxide to produce hydroxyl radical. The mechanism of the generation of hydroxyl radical in the proposed system was confirmed. This study established a simple and inexpensive method for the evaluation of the scavenging ability of some compounds on hydroxyl radicals

    Investigation of the anthracene-nitroxide hybrid molecule as a probe for hydroxyl radicals

    Get PDF
    A new method for the determination of hydroxyl radicals is proposed. The method is based on the use of a hybrid molecule consisting of a fluorescent chromophore, anthracene, and a nitroxide radical. In the hybrid molecule, the nitroxide quenches the fluorescence of anthracene strongly. The reaction of hydroxyl radicals with dimethyl sulfoxide generates quantitatively methyl radicals, which then combine with the nitroxide moiety of the hybrid molecules to result in an increase in the fluorescence intensity. The fluorescence increase is proportional to the concentration of hydroxyl radicals. The proposed method is capable of detecting hydroxyl radicals generated in the Fenton system. It is a simple and sensitive technique for the determination of hydroxyl radicals

    Dual pulse shaping transmission with complementary nyquist pulses

    Full text link
    © 2019 IEEE. The concept of complementary Nyquist pulse is introduced in this paper. Making use of a half rate Nyquist pulse and its complementary one, a dual pulse shaping transmission scheme is proposed, which achieves full Nyquist rate transmission with only a half of the sampling rate required by conventional Nyquist pulse shaping. This is essential for realizing high-speed digital communication systems with available and affordable data conversion devices. The condition for cross-symbol interference free transmission with the proposed dual pulse shaping is proved in theory, and two classes of ideal complementary Nyquist pulses are formulated assuming raised-cosine pulse shaping. Simulation results are also presented to demonstrate the improved spectral efficiency with dual pulse shaping and compare other system performance against conventional Nyquist pulse shaping

    Antifatigue Effect of Millettiae speciosae Champ (Leguminosae) Extract in Mice

    Get PDF
    Purpose: To evaluate whether Millettiae Speciosae Champ. (Leguminosae) can enhance exercise performance as well as ascertain if it a potential functional food material.Methods: The extract of Millettia speciosa Champ. (MSE) was orally administered to mice in 500, 1000, 2000 mg/kg doses to investigate its anti-fatigue effect in both forced swimming and climbing tests. Glycogen, triglyceride (TG), blood urea nitrogen (BUN) and creatine phosphokinase (CK) levels in plasma which can indicate alterations in energy utilization during exercise performance, were determined to analyze the operating exercise mechanisms.Results: The results showed that swimming time to exhaustion was longer in all treated groups (41.06 ± 1.92, 47.84 ± 1.60, 54.00 ± 2.45 min for 500, 10000 and 2000 mg/kg doses, respectively) than for control (19.45 ± 0.62 min, p < 0.05). The middle and high doses of MSE-treated groups significantly prolonged the climbing time compared with control (p < 0.05). Furthermore, MSE reduced the content of TG significantly by increasing fat utilization, delayed the accumulation of BUN and decreased the level of CK (p < 0.05). In addition, administration of MSE significantly protected the depletion of muscle glycogen when compared with control (p < 0.05).Conclusion: The results show for the first time that Millettia speciosa Champ. (Leguminosae) has significant anti-fatigue activity, and also suggest that it is a potential functional food material.Keywords: Radix millettiae speciosae, Anti-fatigue activity, Exercise performance, Serum urea nitrogen, Gastrocnemius muscle glycogen, Triglyceride, Functional foo

    Prediction of migratory routes of the invasive fall armyworm in eastern China using a trajectory analytical approach

    Get PDF
    This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record BACKGROUND: The fall armyworm (FAW), an invasive pest from the Americas, is rapidly spreading through the Old World, and has recently invaded the Indochinese Peninsula and southern China. In the Americas, FAW migrates from winter-breeding areas in the south into summer-breeding areas throughout North America where it is a major pest of corn. Asian populations are also likely to evolve migrations into the corn-producing regions of eastern China, where they will pose a serious threat to food security. RESULTS: To evaluate the invasion risk in eastern China, the rate of expansion and future migratory range was modelled by a trajectory simulation approach, combined with flight behavior and meteorological data. Our results predict that FAW will migrate from its new year-round breeding regions into the two main corn-producing regions of eastern China (Huang-Huai-Hai Summer Corn and Northeast Spring Corn Regions), via two pathways. The western pathway originates in Myanmar and Yunnan, and FAW will take four migration steps (i.e. four generations) to reach the Huang-Huai-Hai Region by July. Migration along the eastern pathway from Indochina and southern China progresses faster, with FAW reaching the Huang-Huai-Hai Region in three steps by June and reaching the Northeast Spring Region in July. CONCLUSION: Our results indicate that there is a high risk that FAW will invade the major corn-producing areas of eastern China via two migration pathways, and cause significant impacts to agricultural productivity. Information on migration pathways and timings can be used to inform integrated pest management strategies for this emerging pest.Biotechnology & Biological Sciences Research Council (BBSRC)CABI Bioscienc

    Co-localization of Pirt protein and P2X2 receptors in the mouse enteric nervous system

    Get PDF
    P2X2 receptors, with other P2X receptor subtypes, have an important role mediating synaptic transmission in regulating the functions of the gastrointestinal tract. Our recent work has found a new regulator of P2X receptor function, called phosphoinositide-interacting regulator of transient receptor potential channels (Pirt). In the present work, we have shown that Pirt immunoreactivity was localized in nerve cell bodies and nerve fibers in the myenteric plexus of the stomach, ileum, proximal, and distal colon and in the submucosal plexus of the jejunum, ileum, proximal, and distal colon. Almost all the Pirt-immunoreactive (ir) neurons were also P2X2-ir, and co-immunoprecipitation experiments have shown that Pirt co-precipitated with the anti-P2X2 antibody. This work provides detailed information about the expression of Pirt in the gut and its co-localization with P2X2, indicating its potential role in influencing P2X2 receptor function

    Field Emission Properties and Fabrication of CdS Nanotube Arrays

    Get PDF
    A large area arrays (ca. 40 cm2) of CdS nanotube on silicon wafer are successfully fabricated by the method of layer-by-layer deposition cycle. The wall thicknesses of CdS nanotubes are tuned by controlling the times of layer-by-layer deposition cycle. The field emission (FE) properties of CdS nanotube arrays are investigated for the first time. The arrays of CdS nanotube with thin wall exhibit better FE properties, a lower turn-on field, and a higher field enhancement factor than that of the arrays of CdS nanotube with thick wall, for which the ratio of length to the wall thickness of the CdS nanotubes have played an important role. With increasing the wall thickness of CdS nanotube, the enhancement factorβdecreases and the values of turn-on field and threshold field increase
    corecore