检索结果-南通市图书馆

Taxotere resistance in SUIT Taxotere resistance in pancreatic carcinoma cell line SUIT 2 and its sublines

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2001年第6期7卷 855-859页

作者： edgar Staren Takeshi lwamura HubertAppert JohnHoward Department of Surgery Medical College of OhioToledoOhioUSA Department of Surgery Miyazaki Medical CollegeMiyazakiJapan

AIM: To investigate the specific mechanisms of intrinsic and acquired resistance to taxotere (TXT) in pancreatic adenocarcinoma (PAC). METHODS: MTT assay was used to detect the sensitivity of PAC cell line SUIT-2 and its sublines (S-007, S-013, S-020, S-028 and TXT selected SUIT-2 cell line, S2/TXT) to TXT. Mdr1 (P-gp), multidrug resistance associated protein (MRP), lung resistance protein (LRP) and beta-tubulin isotype gene expressions were detected by RT-PCR. The functionality of P-gp and MRP was tested using their specific blocker verapamil (Ver) and indomethacin (IMC), respectively. The transporter activity of P-gp was also confirmed by Rhodamine 123 accumulation assay. RESULTS: S-020 and S2/TXT were found to be significantly resistant to TXT(19 and 9.5-fold to their parental cell line SUIT-2, respectively). RT-PCR demonstrated strong expression of Mdr1 in these two cell lines, but weaker expression or no expression in other cells lines. MRP and LRP expressions were found in most of these cell lines. The TXT-resistance in S2-020 and S2/TXT could be reversed almost completely by Ver, but not by IMC. Flow cytometry showed that Ver increased the accumulation of Rhodamine-123 in these two cell lines. Compared with S-020 and SUIT-2, the levels of beta-tubulin isotype II, III expressions in S-2/TXT were increased remarkably. CONCLUSION: The both intrinsic and acquired TXT-related drug resistance in these PAC cell lines is mainly mediated by P-gp, but had no relationship to MRP and LRP expressions. The increases of beta-tubulin isotype II, III might be collateral changes that occur when the SUIT-2 cells are treated with TXT.

关键词： Drug Resistance, Neoplasm Taxoids Antineoplastic Agents, Phytogenic Carcinoma Humans Paclitaxel derivatives Pancreatic Neoplasms Research Support, Non-U.S. Gov't Tumor Cells, Cultured

Frequency Stability of Power System with Large Share of Wind Power Under Storm Conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2020年第2期8卷 219-228页

作者： Kaushik Das Feng Guo edgar Nuno Nicolaos A.Cutululis the Department of Wind Energy Technical University of Denmark(DTU)RiseDenmark Suzlon Energy Limited RostockGermany

The operation of transmission systems with large share of wind power is specially challenging under storm *** the stormy wind speed conditions,wind turbine protection system is designed to shut down the turbine to avoid excessive mechanical *** sudden loss of wind power from large offshore plants is difficult to forecast accurately,which results in a large amount of power *** severity of such a wind power imbalance towards frequency stability needs to be studied for the future power *** addition,the overhead transmission lines can also be affected during storms,thereby increasing their probability of failure in the operation of power system under the islanded *** paper investigates how the stormy weather can threaten the frequency stability of future Danish power system with large share of wind power and how to avoid the frequency instability through proper control and defence strategies such as high-voltage direct current(HVDC)control and load *** studies are performed for ramp rates of HVDC control,load shedding strategies,inertia of the system with different volumes of disturbances to understand their impact on frequency stability.

关键词： Emergency control frequency stability storm security wind power

The reversed intra- and extracellular pH in tumors as a unified strategy to chemotherapeutic delivery using targeted nanocarriers

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2021年第8期11卷 2243-2264页

作者： edgar Pérez-Herrero Alberto Fernández-Medarde Departamento de Ingeniería Química y Tecnología Farmacéutica Universidad de La LagunaLa Laguna 38206TenerifeSpain Instituto Universitario de Bio-Orgánica Antonio González Universidad de La LagunaLa Laguna 38206TenerifeSpain Instituto Universitario de Tecnologías Biomédicas Universidad de La LagunaLa Laguna 38200TenerifeSpain Instituto de Biología Molecular y Celular Del Cáncer Centro de Investigación Del Cáncer(USAL-CSIC)Salamanca 37007Spain

Solid tumors are complex entities,comprising a wide variety of malignancies with very different molecular *** this,they share a set of characteristics known as"hallmarks of cancer"that can be used as common therapeutic ***,every tumor needs to change its metabolism in order to obtain the energy levels required for its high proliferative rates,and these adaptations lead to alterations in extra-and intracellular *** changes in p H are common to all solid tumors,and can be used either as therapeutic targets,blocking the cell proton transporters and reversing the pH changes,or as means to specifically deliver anticancer *** this review we will describe how proton transport inhibitors in association with nanocarriers have been designed to block the pH changes that are needed for cancer cells to survive after their metabolic *** will also describe studies aiming to decrease intracellular pH in cancer using nanoparticles as molecular cages for protons which will be released upon UV or IR light ***,we will comment on several studies that have used the extracellular pH in cancer for an enhanced cell internalization and tumor penetration of nanocarriers and a controlled drug delivery,describing how nanocarriers are being used to increase drug stability and specificity.

关键词： pH-Gradient inversion Metabolism of glucose Proton transport inhibitors Proton-caged carriers Chemotherapy Targeted drug delivery pH-Sensitive nanocarriers Warburg effect Cancer

Semantic framework of event detection in emergency situations for smart buildings

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Digital Communications and Networks 2022年第1期8卷 64-79页

作者： Yudith Cardinale Gabriel Freites edgar Valderrama Ana Aguilera Chinnapong Angsuchotmetee Departamento de Computacidn Universidad Simon BolivarCaracasVenezuela Escuela de Ingenieria Informatica Universidad de ValparaisoValparaisoChile Faculty of Science Prince of Songkla University Thailand

Multimedia Sensor Networks(MSNs)have enhanced the ability to analyze the environment and provide responses based on its current ***,MSNs are composed of scalar and multimedia sensors that have fixed ***,given the advancement of smart mobile device technologies,it is currently possible to dynamically integrate mobile sensors into *** this paper,we propose a formal platform to manage MSNs and the data gathered from them to detect complex *** main contributions include:M^(2)SSN-Onto,a Mobile and Multimedia Semantic Sensor Networks Ontology;Py-CEMiD,an engine for detecting complex events and generate reactions to them;a mobile device location engine to locate mobile sensors;and a proof-of-concept in the context of detecting emergency situations in smart *** scenarios are validated for emergency events,combining simulated sensor measurements with real measurements of mobile *** show complex events can be detected in near real time(less than 1 s).

关键词： Multimedia sensor network Semantic web Event processing Ontology Geolocalisation

Technical problems produced by the Bravo pH test in nonerosive reflux disease patients

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第25期16卷 3183-3186页

作者： Andrés de Hoyos edgar Alain Esparza Department of Gastroenterology Angeles Del Pedregal Hospital México City 10700 México Facultad Mexicana de Medicina Univer-sidad La Salle Internal Medicine México City 14000 México

AIM: To evaluate the technical failures of the Bravo pH test in a population with nonerosive gastroesophageal reflux disease. METHODS: Over the course of a year, we prospectively studied a population of 66 nonerosive reflux disease patients who received a Bravo pH test. The number and frequency of all technical failures were documented, quantified and analyzed. RESULTS: A total of 66 patients, with a mean age of 41.7 years, were studied. Technical failures occurred in 15.15% of the sample. The most frequent failures were due to poor data reception (4.5%), early dislodgement (4.5%) and capsule removal (6.1%). CONCLUSION: The Bravo capsule pH test involves a low but non-negligible rate of technical problems, a fact that must always be considered by physicians.

关键词： Bravo test Capsule dislodgement Nonerosive reflux disease Poor data reception Technical problems

Effects of Taxotere on invasive potential and multidrug resistance phenotype in pancreatic carcinoma cell line SUIT-2

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2001年第1期7卷 143-148页

作者： edgar Staren Takeshi Iwamura Hubert Appert John Howard Department of Surgery Medical College of Ohio Toledo Ohio USA Department of Surgery Miyazaki Medical College Miyazaki Japan

INTRODUCTIONDevelopment of drug-resistance to chemotherapyand subsequent metastasis of tumor are primarilyresponsible for treatment failure and the death fromcancer. There have been many previous studies onthe relationship between expression of multidrugresistance (MDR) phenotype P-glycoprotein (P-gp)and the malignant properties of tumors, but theresults are often conflicting[1-8]. The difference intumor types or MDR phenotype induced by specificagents might account for this discrepancy. Taxotere(TXT), a member of the family of taxanes, hasantitumor activity through its effect of promotingthe polymerization of tubulin[9,10].

关键词： Carcinoma Pancreatic Neoplasms Taxoids Antineoplastic Agents, Phytogenic Biocompatible Materials Collagen Drug Combinations Drug Resistance, Multiple Drug Resistance, Neoplasm Fluorescent Dyes Humans In Vitro Laminin Neoplasm Invasiveness P-Glycoprotein Paclitaxel derivatives Phenotype Proteoglycans RNA, Neoplasm Research Support, Non-U.S. Gov't Rhodamine 123 Tumor Cells, Cultured

An Improved Hybrid Indoor Positioning Algorithm via QPSO and MLP Signal Weighting

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第1期74卷 379-397页

作者： edgar Scavino Mohd Amiruddin Abd Rahman Zahid Farid Department of Physics Faculty of ScienceUniversiti Putra MalaysiaUPM Serdang43400Malaysia Department of Electrical Engineering Abasyn UniversityKhyber-PakhtunkhwaPakistan

Accurate location or positioning of people and self-driven devices in large indoor environments has become an important necessity The application of increasingly automated self-operating moving transportation units,in large indoor spaces demands a precise knowledge of their *** like WiFi and Bluetooth,despite their low-cost and availability,are sensitive to signal noise and fading *** these reasons,a hybrid approach,which uses two different signal sources,has proven to be more resilient and accurate for the positioning determination in indoor ***,this paper proposes an improved hybrid technique to implement a fingerprinting based indoor positioning,using Received Signal Strength information from available Wireless Local Area Network access points,together with the Wireless Sensor Networks *** signals were recorded on a regular grid of anchor points,covering the research *** optimization was performed by relative signal weighting,to minimize the average positioning error over the research *** optimization process was conducted using a standard Quantum Particle Swarm Optimization,while the position error estimate for all given sets of weighted signals was performed using aMultilayer Perceptron(MLP)neural *** to our previous research works,the MLP architecture was improved to three hidden layers and its learning parameters were finely *** experimental results led to the 20%reduction of the positioning error when a suitable set of signal weights was calculated in the optimization *** final achieved value of 0.725 m of the location incertitude shows a sensible improvement compared to our previous results.

关键词： QPSO indoor localization fingerprinting neural networks WiFi WSN

Photo-Induced Water Oxidation Based on a Mononuclear Cobalt(II)Complex

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2014年第6期32卷 467-473页

作者： Hongyan Wang Yongbin Lu edgar Mijangos Anders Thapper Key Laboratory for Mechanical and Environmental Behavior of Tubular Goods Tubular Goods Research Institute of CNPCXi'anShaannxi 710065China Department of Chemistry-Ångström Laboratory Uppsala UniversityUppsala 75120Sweden Research Institute of Yanchang Petroleum(Group)CO.LTD Xi'anShaanxi 710075China

Photo-induced water oxidation based on first row transition metal complexes has drawn much attention recently as a part of the efforts to design systems for solar fuel ***,the classic tetradentate ligand TPA(tris(2-pyridylmethyl)amine)is used together with cobalt(II)in CH_(3)CN to form a mononuclear cobalt complex[Co(TPA)Cl]*** crystal X-ray diffraction shows that[Co(TPA)Cl]Cl is composed of discrete cationic units with a penta-coordinate cobalt center,along with chloride counter *** borate buffer,the Co complex acts as a water oxidation catalyst,as shown by the presence of a catalytic wave in *** visible light irra-diation,in the presence of photosensitizer and electron acceptor,the Co complex catalyzes O2 evolution with a turnover frequency(TOF)of 1.0 mol(O_(2))·mol(Co)^(-1)·s^(-1)and a turnover number(TON)of 55 mol(O_(2))·mol(Co)^(-1)in pH 8 borate buffer.

关键词： water splitting photosynthesis cobalt ligand design electron transfer

High resolution, binder-free investigation of the intrinsic activity of immobilized NiFe LDH nanoparticles on etched carbon nanoelectrodes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2018年第11期11卷 6034-6044页

作者： Patrick Wilde Stefan Barwe Corina Andronescu Wolfgang Schuhmann edgar Ventosa Analytical Chemistry - Center for Electroche.mical Sciences (CES) Ruhr-Universitat Bochum Universitasstr. 150 D-44780 Bochum Germany IMDEA Energy Avda. Ramo de la Sagra 3 28935 Motoles Spain

The determination of the intrinsic properties of nanomaterials is essential for their optimization as electrocatalysts, however it poses great challenges from the standpoint of analytical tools and methods. Herein, we report a novel methodology that allows for a binder-free investigation of electrocatalyst nanoparticles. The potential-assisted immobilization of a non-noble metal catalyst, i.e., nickel-iron layered double hydroxide (NiFe LDH) nanoparticles, was employed to directly attach small nanoparticle ensembles from a suspension to the surface of etched carbon nanoelectrodes. The dimensions of this type of electrodes allowed for the immobilization of the catalyst material below the picogram scale and resulted in a high resolution towards the faradaic current response. In addition the effect of the electrochemical aging on the intrinsic activity of the catalyst was investigated in alkaline media by means of continuous cyclic voltammetry. A change in the material properties could be observed, which was accompanied by a substantial decrease in its intrinsic activity.

关键词： oxygen evolution reaction nickel-iron layered double hydroxide (NiFe LDH) immobilization nanoelectrocatalysis nanoelectrodes nanoimpacts