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Review of endoscopic radiofrequency in biliopancreatic tumours with emphasis on clinical benefits, controversies and safety

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World Journal of Gastroenterology 2016年第37期22卷 8257-8270页

作者： María-Victoria.alvarez-Sánchez Bertrand Napoléon Department of Gastroenterology Complejo Hospitalario Universitario de Pontevedra Instituto de Investigación Sanitaria Galicia Sur Department of Gastroenterology Ramsay Générale de Santé Private Hospital Jean Mermoz

Most pancreatic cancers and extrahepatic cholangiocarcinomas are unresectable at the time of diagnosis, and even in case of a resectable cancer, for elderly or patients with coexistent comorbidities, surgery is not an option. Current treatment alternatives in these scenarios are very limited. Biliary stenting with selfexpanding metal stents(SEMS) is the mainstay palliative treatment of biliary obstruction due to unresectable pancreatic cancer or cholangiocarcinoma. Nevertheless, more than 50% of SEMS become occluded after 6 mo due to tumour over- and ingrowth, leading to hospital readmissions and reinterventions that significantly impair quality of life. Regimes of chemotherapy or chemoradiotherapy also provide minimal survival benefits. Therefore, novel therapies are eagerly awaited. Radiofrequency(RF) energy causes coagulative necrosis leading to local destruction of the accessed malignant tissue and has an established role in the treatment of malignancies in several solid organs, especially liver cancers. However, pancreatic and extrahepatic biliary cancers are not easily accessed by a percutaneous route, making the procedure dangerous. Over the past five years, the development of dedicated devices compatible with endoscopic instruments has offered a minimally invasive option for RF energy delivery in biliopancreatic cancers. Emerging experience with endoscopic RF ablation(RFA) in this setting has been reported in the literature, but little is known about its feasibility, efficacy and safety. A literature review makes it clear that RFA in biliopancreatic tumours is feasible with high rates of technical success and acceptable safety profile. Although available data suggest a benefit of survival with RFA, there is not enough evidence to draw a firm conclusion about its efficacy. For this reason, prospective randomized trials comparing RFA with standard palliative treatments with quality-of-life and survival endpoints are required. Anecdotal reportshave also highlig

关键词： Radiofrequency ablation Pancreatic tumour Endobiliary radiofrequency Cholangiocarcinoma Biliary stricture

Power-law Distribution of Normal Fault Displacement and Length and Estimation of Extensional Strain due to Normal Faults:A Case Study of the Sierra de San Miguelito, Mexico

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Acta Geologica Sinica(English Edition) 2005年第1期79卷 36-42页

作者： XUShunshan A.F.NIETO-SAMANIEGO S.A.ALANIZ-alvarez InstitutoMexicanodelPetrǒleo ProgramaYNFEjeCentralLázaroCárdenasNo.152Col.SanBartoloAtepehuacánC.P.07730 UniversidadNacionalAutǒnomadeMěxico CentrodegeocienciaApartadoPostal1-74276001QuerětaroQro.Měxoco／／InstituteofGeomechnicsChineseAcademyofGeologicalSciencesBeijing100081China.

The Sierra de San Miguelito is a relatively uplifted area and is constituted by a large amount of silicic volcanic rocks with ages from middle to late Cenozoic. The normal faults of the Sierra de San Miguelito are Domino-style and nearly parallel. The cumulative length and displacement of the faults obey power-law distribution. The fractal dimension of the fault traces is -1.49. Using the multi-line one-dimensional sampling, the calculated exponent of cumulative fault displacements is -0.66. A cumulative curve combining measurements of all four sections yielded a slope of -0.63. The displacement-length plot shows a non-linear relationship and large dispersion of data. The large dispersion in the plot is mainly due to the fault linkage during faulting. An estimation of extensional strain due to the normal faults is ca. 0.1830. The bed extension strain is always less than or equal to the horizontal extension strain. The deformation in the Sierra de San Miguelito occurred near the surface, producing pervasive faults and many faults are too small to appear in maps and sections at common scales. The stretching produced by small faults reach ca. 33% of the total horizontal elongation.

关键词： power-law distribution normal faults small faults finite strain Mexico

Noncoding RNAs in cancer and cancer stem cells

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Chinese Journal of Cancer 2013年第11期32卷 582-593页

作者： Tianzhi Huang Angel alvarez Bo Hu Shi-Yuan Cheng The Ken & Ruth Davee Department of Neurology Northwestern University Feinberg School of MedicineChicagoIL 60611USA Northwestern Brain Tumor Institute Northwestern University Feinberg School of MedicineChicagoIL 60611USA The Robert H.Lurie Comprehensive Cancer Center Northwestern University Feinberg School of MedicineChicagoIL 60611USA Center of Molecular Medicine Northwestern University Feinberg School of MedicineChicagoIL 60611USA

In recent years, it has become increasingly apparent that noncoding RNAs(ncRNA) are of crucial importance for human cancer. The functional relevance of ncRNAs is particularly evident for microRNAs(miRNAs) and long noncoding RNAs(lncRNAs). miRNAs are endogenously expressed small RNA sequences that act as post-transcriptional regulators of gene expression and have been extensively studied for their roles in cancers, whereas lncRNAs are emerging as important players in the cancer paradigm in recent years. These noncoding genes are often aberrantly expressed in a variety of human cancers. However, the biological functions of most ncRNAs remain largely unknown. Recently, evidence has begun to accumulate describing how ncRNAs are dysregulated in cancer and cancer stem cells, a subset of cancer cells harboring self-renewal and differentiation capacities. These studies provide insight into the functional roles that ncRNAs play in tumor initiation, progression, and resistance to therapies, and they suggest ncRNAs as attractive therapeutic targets and potentially useful diagnostic tools.

关键词：非编码RNA 干细胞癌症 miRNA RNA序列生物学功能微RNA 基因表达

3D finite element method （FEM） simulation of groundwater flow during backward erosion piping

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Frontiers of Structural and Civil Engineering 2014年第2期8卷 160-166页

作者： Kristine VANDENBOER vera van BEEK Adam BEZUIJEN Department of Civil Engineering Ghent University Ghent 9000 Belgium Deltares Delft 2628 Netherlands Section Geoengineering Delft University of Technology Delft 2628 Netherlands

Backward erosion piping is an important failure mechanism for cohesive water retaining structures which are founded on a sandy aquifer. At present, the prediction models for safety assessment are often based on 2D assumptions. In this work, a 3D numerical approach of the groundwater flow leading to the erosion mechanism of backward erosion piping is presented and discussed. Comparison of the 2D and 3D numerical results explicitly demonstrates the inherent 3D nature of the piping phenomenon. In addition, the influence of the seepage length is investigated and discussed for both piping initiation and piping progression. The results clearly indicate the superiority of the presented 3D numerical model compared to the established 2D approach. Moreover, the 3D numerical results enable a better understanding of the complex physical mechanism involved in backward erosion piping and thus can lead to a significant improvement in the safety assessment of water retaining structures.

关键词： backward erosion piping groundwater flow 3D finite element method (FEM)

Analytical method to measure bending deformations in prismatic optical films

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Chinese Optics Letters 2016年第4期14卷 59-63页

作者： Berta Garcia-Fernandez Antonio alvarez Fernandez-Balbuena Daniel-Vazquez-Molini Department of Optics Faculty of Optics and Optometry University Complutense of Madrid Madrid 28040 Spain Department of Forest and Environmental Engineering and Management School of Forestry Engineering Polytechnic University of Madrid Madrid 28040 Spain

The aim of this work is to provide an analytical method based on experimental measurements in order to obtain the prismatic film deformation for different curvatures of hollow cylindrical prismatic light guides(CPLGs). To conform to cylindrical guides it is necessary to bend the film to guide the light; changes induced by curving the film give rise to deformation shifts. Light losses affected by deformation are experimentally evaluated and numerically analyzed. The effect of deformation on prism angle is especially increased for CPLGs of curvatures higher than 20 m_1. An experimental method for the accurate transmittance of measurements related to bending is presented.

关键词：弯曲测量光学薄膜变形分析棱镜空心圆柱测量分析变形位移数值分析

Mitochondrial Sulfide Detoxification Requires a Functional Isoform O-Acetylserine（thiol）lyase C in Arabidopsis thaliana

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Molecular Plant 2012年第6期5卷 1217-1226页

作者： Consolacien alvarez Irene Garcia Luis C Romero Cecilia Gotor Instituto de Bioquimica Vegetal y Fotosintesis Consejo Superior de Investigaciones Cientificas y Universidad de Sevilla Avda. Am~rico Vespucio 49 41092Sevilla Spain

In non-cyanogenic species, the main source of cyanide derives from ethylene and camalexin biosyntheses. In mitochondria, cyanide is a potent inhibitor of the cytochrome c oxidase and is metabolized by the β-cyanoalanine synthase CYS-C1, catalyzing the conversion of cysteine and cyanide to hydrogen sulfide and β-cyanoalanine. The hydrogen sulfide released also inhibits the cytochrome c oxidase and needs to be detoxified by the O-acetylserine（thiol）lyase mitochondrial isoform, OAS-C, which catalyzes the incorporation of sulfide to O-acetylserine to produce cysteine, thus generating a cyclic pathway in the mitochondria. The loss of functional OAS-C isoforms causes phenotypic characteristics very similar to the loss of the CYS-C1 enzyme, showing defects in root hair formation. Genetic complementation with the OAS-Cgene rescues the impairment of root hair elongation, restoring the wild-type phenotype. The mitochondria compromise their capacity to properly detoxify cyanide and the resulting sulfide because the latter cannot re-assimilate into cysteine in the oas-c null mutant. Consequently, we observe an accumulation of sulfide and cyanide and of the alternative oxidase, which is unable to prevent the production of reactive oxygen species probably due to the accumulation of both toxic molecules. Our results allow us to suggest that the significance of OAS-C is related to its role in the proper sulfide and cyanide detoxification in mitochondria.

关键词： alternative oxidase Arabidopsis thaliana cysteine cyanide β-cyanoalanine synthase O-acetylserine(thiol)-lyase reactive oxygen species root hair sulfide.

Review of enhancement for ocean thermal energy conversion system

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Journal of Ocean Engineering and Science 2023年第5期8卷 533-545页

作者： Safaa Malik Abbas HendDakhelSkhaal Alhassany David vera Francisco Jurado Department of Electrical Engineering University of Jaen23700EPS LinaresJaenSpain

Ocean thermal energy conversion(OTEC)is a renewable energy source that uses differences in ocean water temperature between warm surface and cold depth to generate *** is an essential link in the carbon neutrality chain and one of the rising sectors of the ocean *** paper provides an overview of studies on closed thermodynamic cycles and the numerous difficulties that OTEC technology faces.A description of the thermodynamic cycles incorporating mixed or pure working fluids,as well as the implications of different working fluids on cycle efficiency were also *** in condensing and evaporating temperatures induced by variations in heat resources affect the efficiency of cycles with pure working *** strategies,such as intermediate extraction regeneration and heat recovery of ammonia-depleted solution can increase the thermal efficiency with mixed working *** addition,the impact of the ejector on the cycle’s performance is ***,the efficiency-improving strate-gies are described and *** efficiency can increase using suitable working fluids and taking steps to maximize the rate of ocean thermal *** establish which approach is the most effective,different methods have been evaluated and compared under identical operating conditions.

关键词： Ocean thermal energy conversion Organic rankine cycle Ammonia-water Liquid-vapor ejector Vapor-vapor ejector

Model acupuncture point:Bone marrow-derived stromal stem cells are moved by a weak electromagnetic field

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World Journal of Stem Cells 2016年第10期8卷 342-354页

作者： Artem N Emelyanov Marina V Borisova vera V Kiryanova Laboratory of High Laser and Magnetic Technology North-Western State Medical University Training Laboratory of Physical Chemistry Institute of ChemistrySt. Petersburg State University Department of Physical Therapy and Rehabilitation North-Western State Medical University

AIM To show the existence of a structural formative role of magnetic fields(MFs) with respect to biological objects by using our proposed model of an *** We introduced a magnetised 10-100 μT metal rod(needle) into culture dishes with a negatively charged working surface and observed during 24 h how cells were arranged by MFs and by electrical fields(EFs) when attached. Rat and human bone marrow-derived stromal stem cells(r BMSCs and h BMSCs), human nonadherent mononuclear blood cells, NCTCs and A172 cells, and Escherichia coli(E. coli) were evaluated. The dish containing BMSCs was defined as the model of an acupoint. r BMSCs proliferative activity affected by the needle was investigated. For investigating electromagnetic field structures, we used the gas discharge visualisation(GDV) *** During 24 h of incubation in 50-mm culture dishes, BMSCs or the nonadherent cells accumulated into a central heap in each dish. BMSCs formed a torus(central ring) with an inner diameter of approximately10 mm only upon the introduction of the needle in the centre of the dish. The cells did not show these effects in 35- or 90-mm culture dishes or hydrophobic dishes or rectangular cuvettes. NCTCs and A172 cells showed unstable the effects and only up to two weeks after thawing. Moreover, we observed that the appearance of these effects depended on the season. In winter, BMSCs showed no the effects. GDV experiments revealed that the resonant annular illumination gradually formed from 10 to 18-20 s in polar solutions with and without cell suspension of BMSCs, NCTCs and E. coli when using circular 50-mm dishes, stimulation at 115 V and switching of the electrode poles at 1 kH z. All these data demonstrate the resonant nature of the central ring. Significant influence of MFs on the rB MSC proliferation rate was not *** BMSCs can be moved by MFs when in the presence of a constant EF and MF, when the cells are in the responsive functional state, and whe

关键词： Stem cell movement Magnetic targeting Acupuncture Model acupoint Frizzled-related protein Biology resonance Cytoplasm movement Glycocalyx

Availability assessment of voltage source converter HVDC grids using optimal power flow-based remedial actions

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High Voltage 2020年第5期5卷 523-533页

作者： Mario A.Rios Jeffer L.vera Maria F.Perez Department of Electrical Engineering and Electronics School of EngineeringUniversidad de los AndesCra.1 No.18A-12BogotaColombia

This study proposes a methodology for assessing the availability of voltage source converter high-voltage direct current(HVDC)grids based on the enumeration methodology of contingency analysis with N−2 criteria and makes contributions in the computation of remedial actions and the definition and computation of reliability indices applied for HVDC ***,this study proposes the computation of remedial actions based on an optimal power flow,looking to maintain power exchanges between HVDC and high-voltage alternating current grids,when a contingency occurs on the HVDC grid and converter stations or HVDC lines are out of their operating *** the other hand,an HVDC grid has the function of injecting and extracting power from AC interconnected zones,and then traditionally used nodal reliability indices must be modified to indices that reflect the performance of the HVDC network to fulfil its function of interconnection of *** study defines two sets of availability indices applicable to HVDC grids:(i)loss of power and energy extracted from the DC grid to the AC zones and(ii)loss of power and energy injected to AC zones from the DC *** proposed methodology is applied to perform the availability assessment of the CIGRE B4 DC grid test system and the results are presented.

关键词： power indices optimal