期刊文献+
共找到41篇文章
< 1 2 3 >
每页显示 20 50 100
氯化咪唑基离子液体对柴油中含氮化合物选择性脱除作用研究 被引量:12
1
作者 谢莉莉 陈旬 +4 位作者 王绪绪 付贤智 Alain Favre-Reguillon Stephane Pellet-Rostaing Marc Lemaire 《无机化学学报》 SCIE CAS CSCD 北大核心 2008年第6期919-925,共7页
通过N-甲基咪唑和烷基氯的季铵化反应合成出了咪唑环N上烷基取代基碳链长度或者饱和度不同的4种离子液体:氯化1-丁基-3-甲基咪唑(BMImCl)、氯化1-烯丙基-3-甲基咪唑(AlMImCl)、氯化1-苯甲基-3-甲基咪唑(BzMImCl)和氯化-1-辛基-3-甲基咪... 通过N-甲基咪唑和烷基氯的季铵化反应合成出了咪唑环N上烷基取代基碳链长度或者饱和度不同的4种离子液体:氯化1-丁基-3-甲基咪唑(BMImCl)、氯化1-烯丙基-3-甲基咪唑(AlMImCl)、氯化1-苯甲基-3-甲基咪唑(BzMImCl)和氯化-1-辛基-3-甲基咪唑(OcMImCl)。以含咔唑(CAR)和二苯并噻吩(DBT)的甲苯-正十二烷烃溶液作为模拟柴油,测定CAR和DBT在这些离子液体中的相对分配系数,考察了离子液体对氮和硫化物的萃取脱除选择性。结果表明,在这些离子液体中CAR比DBT有更高的分配系数;4种离子液体比较,BMImCl和AlMImCl对CAR的分配系数分别达46和14,对氮和硫化合物的萃取脱除选择性SN/S分别达到125和38。测定了离子液体在模拟柴油的溶解度,发现这4种离子液体在甲苯和正十二烷烃模拟柴油中的溶解度有显著的差别,其中BMImCl和AlMImCl的溶解度相当且都很小。综合结果显示BMImCl具有最佳性能。实验还比较了BMImCl对不同碱性氮杂环化合物的萃取效果,发现其对含硫化合物和碱性含氮化合物的萃取效率随着模拟柴油中甲苯的质量分数的增加而降低,而对中性含氮化合物表现出高萃取效率,且几乎不受甲苯质量分数的影响。对一种含有361 mg·kg-1N和3598 mg·kg-1S的工业柴油,BMImCl对其对中性含氮化合物的萃取效率达到38%,而对相对含量高约十倍的含硫化合物的萃取率仅约有1.7%。综合上述结果表明,氯化1-丁基-3-甲基咪唑盐离子液体对柴油中的中性含氮化合物具有高选择性脱除作用。 展开更多
关键词 离子液体 中性氮化物 萃取 柴油
下载PDF
用核酸原位杂交技术观察细粒棘球绦虫66kDa抗原mRNA在虫体上的细胞定位 被引量:5
2
作者 傅玉才 王进成 +3 位作者 张立民 张壮志 田虹 G Bosquet 《汕头大学医学院学报》 2003年第2期65-66,69,共3页
目的 :用核酸原位杂交技术观察细粒棘球绦虫 6 6kDa抗原mRNA在虫体上的细胞定位以及在虫体发育的不同时期mRNA含量的变化。方法 :以 6 6kDa抗原的cDNA克隆EgA31为模板制备RNA探针 ,与细粒棘球绦虫原头蚴、育囊和成虫虫体进行原位杂交实... 目的 :用核酸原位杂交技术观察细粒棘球绦虫 6 6kDa抗原mRNA在虫体上的细胞定位以及在虫体发育的不同时期mRNA含量的变化。方法 :以 6 6kDa抗原的cDNA克隆EgA31为模板制备RNA探针 ,与细粒棘球绦虫原头蚴、育囊和成虫虫体进行原位杂交实验。结果 :原位杂交实验显示EgA31mRNA主要位于原头蚴和成虫的皮层下某种细胞中 ,并在棘球蚴育囊的生发层中也存在这种细胞。在原头蚴向成虫的发育过程中虫体吸盘处细胞内EgA31mRNA含量显著增加。结论 :含EgA31mRNA的细胞很可能是皮层细胞 ;EgA31蛋白可能参与吸盘上肌纤维的收缩作用并与虫体的免疫逃避功能有关。 展开更多
关键词 核酸原位杂交技术 观察 细粒棘球绦虫 66kDa抗原 MRNA 细胞定位 原位杂交
下载PDF
细粒棘球绦虫66kDa抗原的超微结构定位 被引量:5
3
作者 傅玉才 Simont Peyrol +3 位作者 王进成 张状志 由虹 Georges Bosquet 《汕头大学医学院学报》 2003年第4期193-194,F002,共3页
目的 :确定细粒棘球绦虫 6 6kDa抗原在虫体组织超微结构中的精确定位。方法 :本实验采用金标免疫组织化学方法 ,电镜观察 6 6kDa抗原在细粒棘球绦虫原头蚴及成虫超薄切片中的定位。结果 :该抗原定位于细粒棘球绦虫原头蚴及成虫虫体的体... 目的 :确定细粒棘球绦虫 6 6kDa抗原在虫体组织超微结构中的精确定位。方法 :本实验采用金标免疫组织化学方法 ,电镜观察 6 6kDa抗原在细粒棘球绦虫原头蚴及成虫超薄切片中的定位。结果 :该抗原定位于细粒棘球绦虫原头蚴及成虫虫体的体表、微毛内外、皮层、皮层合体细胞体 (核周体 )内和皮下肌纤维中。结论 展开更多
关键词 细粒棘球绦虫 66kDa抗原 超微结构定位 金标免疫 组织化学方法
下载PDF
Ar^+和He^+离子与C_(60)碰撞后富勒希离子的激发机制
4
作者 魏宝仁 L.Chen +2 位作者 J.Bernard R.Bredy S.Martin 《原子与分子物理学报》 CAS CSCD 北大核心 2004年第B04期213-215,共3页
C60 在与重离子作用下的激发机制与入射离子能量、质量及电荷态有关。核阻止主要出现在低能重离子与C60 的碰撞中 ;而高能轻离子作用下 ,电子阻止迅速增强 ,成为主要的激发方式。本文中直接观察到由弹性碰撞引起的C+ 峰 ,及其丰度依赖... C60 在与重离子作用下的激发机制与入射离子能量、质量及电荷态有关。核阻止主要出现在低能重离子与C60 的碰撞中 ;而高能轻离子作用下 ,电子阻止迅速增强 ,成为主要的激发方式。本文中直接观察到由弹性碰撞引起的C+ 峰 ,及其丰度依赖于入射离子的质量。同时我们还发现电子阻止随入射离子能量 (7~ 2 0keV)增大相应增加 ,这与绝热量子分子动力学计算的结果一致。 展开更多
关键词 核阻止 电子阻止 激发机制
下载PDF
Intra-operative peritoneal lavage for colorectal cancer 被引量:5
5
作者 Guillaume Passot Kayvan Mohkam +1 位作者 Eddy Cotte Olivier Glehen 《World Journal of Gastroenterology》 SCIE CAS 2014年第8期1935-1939,共5页
Free cancer cells can be detected in peritoneal fluid at the time of colorectal surgery.Peritoneal lavage in colorectal surgery for cancer is not used in routine,and the prognostic significance of intraperitoneal free... Free cancer cells can be detected in peritoneal fluid at the time of colorectal surgery.Peritoneal lavage in colorectal surgery for cancer is not used in routine,and the prognostic significance of intraperitoneal free cancer cells(IPCC)remains unclear.Data concerning the technique of peritoneal lavage to detect IPCC and its timing regarding colorectal resection are scarce.However,positive IPCC might be the first step of peritoneal spread in colorectal cancers,which could lead to early specific treatments.Because of the important heterogeneity of IPCC determination in reported studies,no treatment have been proposed to patients why positive IPCC.Herein,we provide an overview of IPCC detection and its impact on recurrence and survival,and we suggest further multi-institutional studies to evaluate new treatment strategies. 展开更多
关键词 PERITONEAL CARCINOMATOSIS COLORECTAL CANCER Free i
下载PDF
动脉粥样硬化斑块炎症影像铁纳米颗粒快速廓清的动物模型初步研究 被引量:6
6
作者 M.Sigovan L.Boussel +4 位作者 A.Sulaiman D.Sappey-Marinier H.Alsaid C.Desbleds-Mansard 王鹤 《国际医学放射学杂志》 2009年第5期495-495,共1页
目的评价应用最近研发的高廓清率超微超顺磁性三氧化二铁(USPIO)检出动脉粥样硬化斑块内血管炎症的能力。材料与方法本研究得到了动物实验伦理委员会的批准。应用人工诱导主动脉粥样硬化的兔模型测试最近引进的USPIO、P904,以标准型U... 目的评价应用最近研发的高廓清率超微超顺磁性三氧化二铁(USPIO)检出动脉粥样硬化斑块内血管炎症的能力。材料与方法本研究得到了动物实验伦理委员会的批准。应用人工诱导主动脉粥样硬化的兔模型测试最近引进的USPIO、P904,以标准型USPIO、ferumoxtran-10作为参照。 展开更多
关键词 动脉粥样硬化斑块 三氧化二铁 廓清率 动物模型 纳米颗粒 斑块炎症 主动脉粥样硬化 影像
下载PDF
Interaction of cetyltrimethylammonium bromide with drug in aqueous/electrolyte solution:A combined conductometric and molecular dynamics method study 被引量:3
7
作者 Md.Anamul Hoque Md.Masud Alam +5 位作者 Mohammad Robel Molla Shahed Rana Malik Abdul Rub Mohammad A.Halim Mohammed Abdullah Khan Farida Akhtar 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第1期159-167,共9页
Interaction between beta-lactum antibiotic drug ciprofloxacin hydrochloride(CFH)and cationic surfactant cetyltrimethylammonium bromide(CTAB)was performed conductometrically in aqueous as well as in the occurrence of d... Interaction between beta-lactum antibiotic drug ciprofloxacin hydrochloride(CFH)and cationic surfactant cetyltrimethylammonium bromide(CTAB)was performed conductometrically in aqueous as well as in the occurrence of different salts(NaCl,KCl as well as NH_4Cl)over the temperature range of 298.15–323.15 K at the regular interval of 5 K.CFH drug has been suggested for the treatment of bacterial infections such as urinary tract infections and acute sinusitis.A clear critical micelle concentration(CMC)was obtained for pure CTAB as well as(CFH+CTAB)mixed systems.The decrease in CMC values of CTAB caused by the addition of CFH reveals the existence of the interaction between the components and therefore it is the indication of micelle formation at lower concentration of CTAB and their CMC values further decrease in attendance of salts.A nonlinear behavior in the CMC versus T plot was observed in all the cases.The ΔG_m^0 values are found to be negative in present study systems demonstrated the stability of the solution.The values of ΔH_m^0 and ΔS_m^0 reveal the existence of hydrophobic and electrostatic interactions between CFH and CTAB.The thermodynamic properties of transfer for the micellization were also evaluated and discussed in detail.Molecular dynamic simulation disclosed that environment of water and salts have impact on the hydrophobic interaction between CFH and CTAB.In water and salts,CTAB adopts spherical micelle in which charged hydrophilic groups are interacted with waters whereas hydrophobic tails form the core of the micelle.This hydrophobic core region is highly conserved and protected.In addition,micelle formation is more favorable in aqueous Na Cl solution than other solutions. 展开更多
关键词 相互作用 溴化物 动力学方法 电解质 学习 分子 尿道感染 表面活化剂
下载PDF
Lorentz force electrical impedance tomography using pulse compression technique 被引量:2
8
作者 孙直申 刘国强 夏慧 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第12期355-360,共6页
Lorentz force electrical impedance tomography (LFEIT) combines ultrasound stimulation and electromagnetic field detection with the goal of creating a high contrast and high resolution hybrid imaging modality. In thi... Lorentz force electrical impedance tomography (LFEIT) combines ultrasound stimulation and electromagnetic field detection with the goal of creating a high contrast and high resolution hybrid imaging modality. In this study, pulse compression working together with a linearly frequency modulated ultrasound pulse was investigated in LFEIT. Experiments were done on agar phantoms having the same level of electrical conductivity as soft biological tissues. The results showed that:(i) LFEIT using pulse compression could detect the location of the electrical conductivity variations precisely; (ii) LFEIT using pulse compression could get the same performance of detecting electrical conductivity variations as the traditional LFEIT using high voltage narrow pulse but reduce the peak stimulating power to the transducer by 25.5 dB; (iii) axial resolution of 1 mm could be obtained using modulation frequency bandwidth 2 MHz. 展开更多
关键词 Lorentz force electrical impedance tomography Hall effect imaging magneto-acousto-electrical tomography linear frequency-modulation pulse compression
下载PDF
Delayed Ionization and Delayed Detachment in Molecules and Clusters 被引量:1
9
作者 F. Lépine B. Baguenard B. Concina M. A. Lebeault C. Bordas 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第2期162-170,共9页
在它的电离阀值上面激动的一个分子的系统的进化取决于包括激动的状态和他们的政变石楠的性质到各种各样的 continua 的很多个参数。管理这进化的过程的一般性质实质上也取决于分子的复杂性,更精确在它的尺寸,状态的密度,和在自由的... 在它的电离阀值上面激动的一个分子的系统的进化取决于包括激动的状态和他们的政变石楠的性质到各种各样的 continua 的很多个参数。管理这进化的过程的一般性质实质上也取决于分子的复杂性,更精确在它的尺寸,状态的密度,和在自由的各种各样的内部度之中的政变石楠的力量上。在这篇论文,我们探讨在在发生在更大的分子或簇的小分子,和推迟的电离占优势的自电离之间的转变的问题。这转变被 Na <SUB>2</SUB> Rydberg 状态的自电离一方面说明,在 fullerene C <SUB>60</SUB>, 推迟了电离并且在另一方面推迟了在小簇阴离子的分开。所有过程在毫微秒激光刺激的情况中被学习,相应于内部精力的相当慢的免职。 展开更多
关键词 自电离 自解离 热电子发射 分子
下载PDF
Continuous frequency and phase spectrograms: a study of their 2D and 3D capabilities and application to musical signal analysis 被引量:1
10
作者 Laurent NAVARRO Guy COURBEBAISSE Jean-Charles PINOLI 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第2期199-206,共8页
A new lighting and enlargement on phase spectrogram(PS)and frequency spectrogram(FS)is presented in this paper.These representations result from the coupling of power spectrogram and short time Fourier transform(STFT)... A new lighting and enlargement on phase spectrogram(PS)and frequency spectrogram(FS)is presented in this paper.These representations result from the coupling of power spectrogram and short time Fourier transform(STFT).The main con-tribution is the construction of the 3D phase spectrogram(3DPS)and the 3D frequency spectrogram(3DFS).These new tools allow such specific test signals as small slope linear chirp,phase jump and small frequency jump to be analyzed.An application case of musical signal analysis is reported.The main objective is to detect small frequency and phase variations in order to characterize each type of sound attack without losing the amplitude information given by power spectrogram. 展开更多
关键词 信号分析 通信技术 频率光谱 相位光谱
下载PDF
Double cholecystectomy in case of accessory gallbladder:Not as easy as two cholecystectomies 被引量:1
11
作者 Benjamin Darnis Kayvan Mohkam +1 位作者 Fran?ois Cauchy Jean-Yves Mabrut 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2019年第1期93-95,共3页
To the Editor:Accessory gallbladders(AG)are rare and their management are usually challenging.These variations are related with an abnormal division of the bile ducts precursors between the 5th and the 12th week of pr... To the Editor:Accessory gallbladders(AG)are rare and their management are usually challenging.These variations are related with an abnormal division of the bile ducts precursors between the 5th and the 12th week of pregnancy.Harlaftis et al.[1]proposed an anatomical classification of these variations based on the embryologic abnormalities described.In type 1 both gallbladders are connected to the common bile duct at the same location.In type 2 the AG can reach either the common bile duct(ductular type)or an intrahepatic biliary duct(trabecular type).In type 3,three gallbladders are present. 展开更多
关键词 gallbladders Harlaftis
下载PDF
Field Application of the Mycorrhizal Fungus <i>Rhizophagus irregularis</i>Increases the Yield of Wheat Crop and Affects Soil Microbial Functionalities 被引量:1
12
作者 Sanaa Wahbi Yves Prin +5 位作者 Tasnime Maghraoui Hervé Sanguin Jean Thioulouse Khalid Oufdou Mohamed Hafidi Robin Duponnois 《American Journal of Plant Sciences》 2015年第19期3205-3215,共11页
The aim of this study was to test the impact of Rhizophagus irregularis, an arbuscular mycorrhizal fungus (AMF), on durum wheat growth and soil microbial functionalities in a field inoculation trial conducted in Moroc... The aim of this study was to test the impact of Rhizophagus irregularis, an arbuscular mycorrhizal fungus (AMF), on durum wheat growth and soil microbial functionalities in a field inoculation trial conducted in Morocco. The results showed that i) the R. irregularis inoculum effectively improved wheat growth, ii) wheat growth promotion depended on the soil mycorrhizal infectivity and iii) functional abilities of soil microflora depended on AMF inoculation. This study confirms that field AMF inoculation can be proposed as an effective agronomic practice in wheat production and as a sustainable cultural practice to manage soil biofunctioning. To fully promote inoculation practices, a better knowledge of AMF ecology has to be acquired to better adapt AMF inoculation to environmental conditions, and thus warrant better yields and agricultural sustainability. 展开更多
关键词 ARBUSCULAR MYCORRHIZAL Fungi Field-Grown WHEAT MYCORRHIZAL FIELD Inoculation Nutrient Uptake Microbial Soil Functions
下载PDF
DC/DC变换器稳定性的分析方法
13
作者 林雪芳 B.Allard +1 位作者 毕津顺 李博 《电气工程与自动化(中英文版)》 2015年第3期35-38,共4页
DC/DC变换器属线性混合系统一类.其稳定性分析必须考虑到它们的切换特性.本文介绍一种简单的稳定性分析方法,它可预测被控制的DC/DC变换器在参数变化条件下可能出现的不稳定性及混沌现象.由于它很容易被加入到集成电路的设计流程中,为集... DC/DC变换器属线性混合系统一类.其稳定性分析必须考虑到它们的切换特性.本文介绍一种简单的稳定性分析方法,它可预测被控制的DC/DC变换器在参数变化条件下可能出现的不稳定性及混沌现象.由于它很容易被加入到集成电路的设计流程中,为集成DC/DC变换器设计师提供了一个有效的辅助设计工具. 展开更多
关键词 DC/DC转换器 稳定性分析 采样数据模型
下载PDF
Combined collision-induced dissociation and photo-selected reaction monitoring mass spectrometry modes for simultaneous analysis of coagulation factors and estrogens
14
作者 Quentin Enjalbert Marion Girod +6 位作者 Jérémy Jeudy Jordane Biarc Romain Simon Rodolphe Antoine Philippe Dugourd Jér?me Lemoine Arnaud Salvador 《Journal of Pharmaceutical Analysis》 SCIE CAS 2014年第3期183-189,共7页
Oral estrogens are directly associated with changes in plasma levels of coagulation proteins. Thus, the detection of any variation in protein concentrations due to estrogen contraceptives, by a simultaneous analysis o... Oral estrogens are directly associated with changes in plasma levels of coagulation proteins. Thus, the detection of any variation in protein concentrations due to estrogen contraceptives, by a simultaneous analysis of both coagulation proteins and estrogens, would be a very informative tool. In the present study, the merit of photo-selected reaction monitoring (SRM), a new analytical tool, was evaluated towards estrogens detection in plasma. Then, SRM and photo-SRM detection modes were combined for the simultaneous analysis of estrogen molecules together with heparin co-factor and factor XIIa, two proteins involved in the coagulation cascade. This study shows that photo-SRM could open new multiplexed analytical routes. 展开更多
关键词 ESTROGEN Coagulation factorprotein METABOLITE Photo-dissociation fragmentation SRM
下载PDF
Postural spinal balance defined by net intersegmental moments: Results of a biomechanical approach and experimental errors measurement
15
作者 Benjamin Blondel Elke Viehweger +7 位作者 Bertrand Moal Patrick Tropiano Jean-Luc Jouve Virginie Lafage Raphael Dumas Stéphane Fuentes Gérard Bollini Vincent Pomero 《World Journal of Orthopedics》 2015年第11期983-990,共8页
AIM: To describe initial results and experimental error measurement of a protocol analyzing Human posture through sagittal intersegmental moments. METHODS: Postural analysis has been recently improved by development o... AIM: To describe initial results and experimental error measurement of a protocol analyzing Human posture through sagittal intersegmental moments. METHODS: Postural analysis has been recently improved by development of three-dimensional radiographic imaging systems. However, in various situations such as global sagittal anterior malalignment interpretation of radiographs may not represent the real alignment of the subject. The aim of this study was to present initial results of a 3D biomechanical protocol. This protocol isobtained in a free standing position and characterizes postural balance by measurement of sagittal intersegmental net moments. After elaboration of a specific marker-set, 4 successive recordings were done on two volunteers by three different operators during three sessions in order to evaluate the experimental error measurement. A supplementary acquisition in a "radiographic" posture was also obtained. Once the data acquired, joint center, length, anatomical frame and the center of mass of each body segment was calculated and a mass affected. Sagittal net intersegmental moments were computed in an ascending manner from ground reaction forces at the ankles, knees, hips and the lumbosacral and thoraco-lumbar spinal junctions. Cervicothoracic net intersegmental moment was calculated in a descending manner.RESULTS: Based on average recordings, clinical interpretation of net intersegmental moments(in N.m) showed a dorsal flexion on the ankles(8.6 N.m), a flexion on the knees(7.5 N.m) and an extension on the hips(8.5 N.m). On the spinal junctions, it was flexion moments: 0.34 N.m on the cervico-thoracic; 6.7 N.m on the thoraco-lumbar and 0.65 N.m on the lumbo-sacral. Evaluation of experimental error measurement showed a small inter-trial error(intrinsic variability), with higher inter-session and inter-therapist errors but without important variation between them. For one volunteer the "radiographic" posture was associated to significant changes compared to the free standing position. CONCLUSION: These initial results confirm the technical feasibility of the protocol. The low intrinsic error and the small differences between inter-session and intertherapist errors seem to traduce postural variability over time, more than a failure of the protocol. Characterization of sagittal intersegmental net moments can have clinical applications such as evaluation of an unfused segment after a spinal arthrodesis. 展开更多
关键词 POSTURE SAGITTAL alignement BIOMECHANICAL evaluation Intersegmental NET MOMENTS
下载PDF
A Rapid Electrophoresis Method on Agarose Gel to Characterise Dairy Protein Aggregates
16
作者 Laetitia Gemelas Pascal Degraeve +2 位作者 Marion Morand Arnaud Hallier Yann Demarigny 《Food and Nutrition Sciences》 2018年第4期325-334,共10页
Heat treatment of milk may cause whey proteins and caseins to form aggregates. These soluble and micellar aggregates and their other properties (size, composition, shape, etc.) can affect the techno-functionalities to... Heat treatment of milk may cause whey proteins and caseins to form aggregates. These soluble and micellar aggregates and their other properties (size, composition, shape, etc.) can affect the techno-functionalities to the milk, conferring interesting or negative features depending on the application in dairy industries. In this study, we propose a new approach to characterise those protein aggregates. SDS-agarose electrophoresis is followed by the calculation of a retention factor (Rf) for each protein spot. Rf allows milk aggregates to be compared qualitatively under the same conditions. This method could be transposed to the dairy industry for a better knowledge of the milk subsequent to heat treatment. 展开更多
关键词 Heat Treatment of MILK DAIRY Protein AGGREGATES AGAROSE GEL ELECTROPHORESIS
下载PDF
Polymorphic multiple hepatocellular adenoma including a non-steatotic HNF1α-inactivated variant
17
作者 Kayvan Mohkam Benjamin Darnis +5 位作者 Jean-Baptiste Cazauran Agnès Rode Anne-Frédérique Manichon Christian Ducerf Brigitte Bancel Jean-Yves Mabrut 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2017年第5期552-555,共4页
To the Editor:Hepatocellular adenomas(HCAs)consist of benign liver tumors favored by the use of oral contraceptives,which preferentially occur in women.[1,2]They expose to the risk of hemorrhage(20%of cases)and more r... To the Editor:Hepatocellular adenomas(HCAs)consist of benign liver tumors favored by the use of oral contraceptives,which preferentially occur in women.[1,2]They expose to the risk of hemorrhage(20%of cases)and more rarely,to the risk of malignant transformation(4%-10%of cases).[3,4]Multiple HCAs,which are defined by the presence of 10 or more 展开更多
关键词 HNF Polymorphic multiple hepatocellular adenoma including a non-steatotic HNF1 HCA
下载PDF
Graphite Nanoplatelets Composite Materials: Role of the Epoxy-System in the Thermal Conductivity
18
作者 Lurayni Diaz-Chacon Renaud Metz +5 位作者 Philippe Dieudonné Jean Louis Bantignies Said Tahir Mehrdad Hassanzadeh Eleida Sosa Reinaldo Atencio 《Journal of Materials Science and Chemical Engineering》 2015年第5期75-87,共13页
Polymers typically have intrinsic thermal conductivity much lower than other materials. Enhancement of this property may be obtained by the addition of conductive fillers. In this research, epoxy nanocomposites with e... Polymers typically have intrinsic thermal conductivity much lower than other materials. Enhancement of this property may be obtained by the addition of conductive fillers. In this research, epoxy nanocomposites with exfoliated graphite nanoplatelets are prepared and characterized. The chosen approach requires no surface treatment and no sophisticated equipments allowing one to produce composites on a pilot scale. A significant increase of the thermal conductivity with the increasing of the graphite fillers content is nevertheless observed on 4 mm thick specimens. Our results viewed in the latest scientific findings suggest that the choice of resin is an important parameter to move towards composite materials with high thermal conductivity. 展开更多
关键词 Composite Epoxy-GnP Thermal Conductivity GRAPHITE NANOPLATELETS EXFOLIATED GRAPHITE
下载PDF
Copy Mean: A New Method to Impute Intermittent Missing Values in Longitudinal Studies
19
作者 Christophe Genolini René écochard Hélène Jacqmin-Gadda 《Open Journal of Statistics》 2013年第4期26-40,共15页
Longitudinal studies are those in which the same variable is repeatedly measured at different times. These studies are more likely than others to suffer from missing values. Since the presence of missing values may ha... Longitudinal studies are those in which the same variable is repeatedly measured at different times. These studies are more likely than others to suffer from missing values. Since the presence of missing values may have an important impact on statistical analyses, it is important that they should be dealt with properly. In this paper, we present “Copy Mean”, a new method to impute intermittent missing values. We compared its efficiency in eleven imputation methods dedicated to the treatment of missing values in longitudinal data. All these methods were tested on three markedly different real datasets (stationary, increasing, and sinusoidal pattern) with complete data. For each of them, we generated nine types of incomplete datasets that include 10%, 30%, or 50% of missing data using either a Missing Completely at Random, a Missing at Random, or a Missing Not at Random missingness mechanism. Our results show that Copy Mean has a great effectiveness, exceeding or equaling the performance of other methods in almost all configurations. The effectiveness of linear interpolation is highly data-dependent. The Last Occurrence Carried Forward method is strongly discouraged. 展开更多
关键词 IMPUTATION Longitudinal Data INTERMITTENT MISSING VALUES
下载PDF
特殊驱动模型矩阵中固定胶粒的诊断生物芯片:用于探测P53基因点突变和Anti-HIV-1衣体蛋白质抗体(英文)
20
作者 C. A. Marquette A. Degiuli L. J. Blum 《光散射学报》 2005年第3期254-255,共2页
The development of biochips for the detection of nucleic acids, proteins or enzyme-substrate interactions has experienced a large increase since those tools were found to provide to researchers and diagnostic companie... The development of biochips for the detection of nucleic acids, proteins or enzyme-substrate interactions has experienced a large increase since those tools were found to provide to researchers and diagnostic companies a rapid sample’s screening. Nevertheless, one of the main handicap for the development in this area appeared to be a lack of generic immobilization procedure for those biologically active compounds; a lack linked in one hand to the obligatory effort to keep active the immobilized biological molecules and in the other hand to the diversity of detection/transduction systems used. The early immobilization procedure on silicon and glass support based on silane technology, still in use for protein and DNA immobilization [1-3] is now in competition with thiol-disulfide techniques [4-6] on gold surface, beads array [7, 8], micro-contact printing [9] and particle lithography [10]. Each of these techniques is used in conjunction with a detection system, most of the time intimately dependent of the immobilization procedure. 展开更多
关键词 驱动模型矩阵 固定胶粒 诊断生物芯片 P53 基因点突变 衣体蛋白质抗体
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部