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汉字海报“形意”转化的设计本源探索 被引量:10
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作者 张爱鹏 《湖南包装》 2020年第4期14-16,28,共4页
通过对汉字本源的解读,感悟汉字的形美与意达的视觉转译过程,再结合分析各具代表性的汉字海报作品,以东方审美视角解析汉字海报"形意"转化的探索路径,用设计的理性表达意象的感性,达到汉字海报设计的意境之美。在传统文化热... 通过对汉字本源的解读,感悟汉字的形美与意达的视觉转译过程,再结合分析各具代表性的汉字海报作品,以东方审美视角解析汉字海报"形意"转化的探索路径,用设计的理性表达意象的感性,达到汉字海报设计的意境之美。在传统文化热潮席卷全球,民族文化回归大众之时,中国设计师也重新审视自身文化的价值。其中,汉字海报设计是再现东方审美的重要载体和媒介,文章分别从汉字海报图形化、符号化、意境化3个方面进行形意转化和视觉表现,表达人与自然天人合一的思想,从而设计出符合东方审美的意境佳作,在广泛传播东方文化的同时,实现中国文化自信。 展开更多
关键词 转化 东方审美 汉字海报 设计本源
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浅谈中学数学数形转化之方法
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作者 张庆波 《希望月报(上)》 2008年第6期75-75,共1页
本文就中学数学数形转化问题,举例探讨了数向形的转化及形向数的转化之方法。
关键词 中学数学数转化 数向 向数
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甲状腺梭形细胞化生4例临床病理分析及文献复习
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作者 梁华 张娇娇 +1 位作者 张冠军 宫惠琳 《诊断病理学杂志》 2022年第1期21-26,共6页
目的探讨甲状腺梭形细胞化生的临床特点、组织病理学特征、诊断和鉴别诊断要点以及生物学行为。方法采用免疫组化EnVision二步法对4例甲状腺的梭形细胞化生,涉及3例结节性甲状腺肿和1例包膜血管浸润型滤泡癌,进行染色,并结合文献分析其... 目的探讨甲状腺梭形细胞化生的临床特点、组织病理学特征、诊断和鉴别诊断要点以及生物学行为。方法采用免疫组化EnVision二步法对4例甲状腺的梭形细胞化生,涉及3例结节性甲状腺肿和1例包膜血管浸润型滤泡癌,进行染色,并结合文献分析其临床病理学特点、免疫组化特征及预后。结果4例中女性2例,男性2例,年龄45~67岁。临床表现:2例发现颈部包块,2例咳嗽、咳痰。肿块最大径3~8 cm。肉眼检查肿瘤包膜完整,切面灰红灰黄色,中央可见灰白区,占肿瘤的28%~40%不等,可囊性变。光镜下表现为梭形细胞呈束状或围绕血管呈漩涡状排列,可见滤泡结构与梭形细胞之间相互移行,梭形细胞温和,未见核分裂象及坏死。免疫表型显示梭形细胞表达vimentin、CK、CK19、Tg、TTF⁃1,E⁃cadherin在梭形细胞中表达减弱至阴性,局灶区表达SMA,Ki⁃67表达率低,不表达神经内分泌标记、Calcitonin、CD34、STAT6、S⁃100、Desmin、HMB45等标记。4位患者经过30~96个月的随访未见复发及转移。结论甲状腺的梭形细胞化生或转化为一种少见甲状腺病变,组织学特点及免疫组化支持梭形细胞来源于滤泡上皮,实质上是上皮向间质的转化。病理诊断主要依靠病理学形态和免疫表型,需与甲状腺梭形细胞病变及肿瘤相鉴别,如梭形细胞型髓样癌、间变性癌、细针穿刺后修复性改变、孤立性纤维性肿瘤等。患者预后好,治疗以手术彻底切除为主,并注意长期随访。 展开更多
关键词 甲状腺肿瘤 细胞化生/转化 结节性甲状腺肿 滤泡癌 免疫组化 临床病理特点 预后
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转化思想在初中数学解题中的应用 被引量:3
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作者 井玉潇 《数学之友》 2022年第3期62-64,共3页
在初中数学解题中,转化思想是一种重要的数学思维.解题中常见的转化方式有:直接转化、降次转化、换元转化与数形转化.在教学中,教师应注重转化的原则和提问方式,适时渗透转化思想,以帮助学生在解题时恰当运用转化方式.
关键词 转化思想 直接转化 降次转化 换元转化 数代入转化 解题方法
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浅谈用数形结合的数学思想方法解题
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作者 高爱军 《数学学习与研究》 2008年第12期108-108,共1页
本文通过举例,来说明用数形结合的思想方法分析解决问题,可以提高解题速度。
关键词 数与转化 交点 距离 斜率
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谈数学学习中的转化思想
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作者 关少英 《中学理科园地》 2012年第3期57-58,共2页
转化思想是数学中的一个重要的数学思想,它应用广泛,贯穿于整个数学的教学和学习中。本文旨在通过其在教学中的点滴运用,引起广大教师对这一重要思想的广泛关注,并有意识地使用它去培养和训练学生的思维以提高教学质量和解题能力。
关键词 数学教学 转化思想 数与转化
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Differential utilization and speciation transformation of orthorhombic α-S_8 and amorphous μ-S by substrate-acclimated mesophilic Acidithiobacillus ferrooxidans 被引量:2
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作者 刘红昌 夏金兰 +3 位作者 聂珍媛 郑雷 马陈燕 赵屹东 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第9期3096-3102,共7页
The utilization and speciation transformation of α-S8 and μ-S by the typical mesophilic acidophilic strain Acidithiobacillus ferrooxidans ATCC 23270 were investigated.A.ferrooxidans cells first acclimated to the ene... The utilization and speciation transformation of α-S8 and μ-S by the typical mesophilic acidophilic strain Acidithiobacillus ferrooxidans ATCC 23270 were investigated.A.ferrooxidans cells first acclimated to the energy source α-S8 or μ-S,respectively.The results of cell growth and sulfur oxidation behavior showed that the strain grown on α-S8 entered slowly(about 1 d later) into the exponential phase,while grew faster in the exponential phase and attained higher maximal cell density and lower p H value than that on μ-S.After bio-corrosion,both of the two sulfur samples were evidently eroded and modified by A.ferrooxidans cells.After growth of A.ferrooxidans,the surface composition of amorphous μ-S became 63.1% μ-S and 36.9% α-S8,and that of orthorhombic α-S8 became 68.3% α-S8 and 31.7% μ-S,while the surface compositions of α-S8 and μ-S in sterile experiment were not changed,indicating that these two elemental sulfur species can be interconverted by A.ferrooxidans. 展开更多
关键词 sulfur utilization sulfur speciation transformation α-S8 μ-S Acidithiobacillus ferrooxidans
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Phase transitions, micro-morphology and its oxidation mechanism in oxidation of ilmenite (FeTiO_3) powder 被引量:5
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作者 肖玮 鲁雄刚 +2 位作者 邹星礼 危雪梅 丁伟中 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第8期2439-2445,共7页
Phase transitions, morphology changes, and oxidation mechanism of the ilmenite oxidation process were investigated. FeTi03 transforms to hematite and rutile when oxidation at 700-800 ℃, and pseudobrookite is formed w... Phase transitions, morphology changes, and oxidation mechanism of the ilmenite oxidation process were investigated. FeTi03 transforms to hematite and rutile when oxidation at 700-800 ℃, and pseudobrookite is formed when the oxidation temperature reaches 900 ℃. The initial ilmenite powder exhibits paramagnetism; however, after being oxidized at the intermediate temperature (800-850 ℃), the oxidation product exhibits weak ferromagnetism. The oxidation mechanism was discussed. The microstructure observations show that a lot of micro-pores emerge on the surfaces of ilmenite particles at the intermediate temperature, which is deemed to be caoable ofenhancin~ the mass transfer ofoxgen during oxidation. 展开更多
关键词 ILMENITE phase transitions MICRO-MORPHOLOGY oxidation mechanism
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Preparation and characterization of Ce-silane-ZrO_2 composite coatings on 1060 aluminum 被引量:3
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作者 左轲 王昕 +1 位作者 柳伟 赵越 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第5期1474-1480,共7页
In order to improve the property of traditional Ce-based conversion coatings, Ce-silane-ZrO2 composite coatings were successfully prepared on 1060 aluminum. The microstructure, chemical element composition and corrosi... In order to improve the property of traditional Ce-based conversion coatings, Ce-silane-ZrO2 composite coatings were successfully prepared on 1060 aluminum. The microstructure, chemical element composition and corrosion resistance of Ce-based conversion coatings and Ce-silane-ZrO2 composite coatings were investigated by SEM, AFM, XPS and EIS analyses. Stacking structure of the composite coating can be observed. The inner layer of the composite coatings mainly consists of oxide and hydroxide of Ce(Ⅲ), and the silane network is composed of the outer layer together with a small amount of Ce(Ⅳ) hydroxide. By adding silane and ZrO2 nanoparticles into Ce-based conversion coatings, the porosity and the micro cracks of the coatings decrease apparently accompanying with the improvement of the corrosion resistance. 展开更多
关键词 ALUMINUM conversion coatings corrosion resistance surface morphology chemical composition
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RELATIONSHIP BETWEEN GROWTH AND MORPHOLOGY OF METARRHIZIUM ANISOPLIAE IN BIOTRANSFORMATION OF STEROID 被引量:2
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作者 阳葵 李晓静 +2 位作者 王积分 段世铎 张鎏 《Transactions of Tianjin University》 EI CAS 2001年第1期1-6,共6页
The fermentation with mold metarrhizium anisopliae has been carried out to determine the relationship between mycelial morphology and growth.Like the biomass concentration,the mycelial morphology seems to be coupled t... The fermentation with mold metarrhizium anisopliae has been carried out to determine the relationship between mycelial morphology and growth.Like the biomass concentration,the mycelial morphology seems to be coupled to growth phases:the fractal dimension,a feature calculated from the morphological images,increases during the late lag phase and the early exponential phase,and culminates at a value near 2.4 at half of the exponential phase.This can be attributed to the marked change of rough and smooth pellet proportions during growth and the change can be well expressed by the fractal analysis of mycelial morphology.The mycelial morphology is also strongly related to the biotransformation activity:a mycelial sample was withdrawn from the culture to use for fractal analysis before the steroid substrate (16α,17α epoxy 4 pregnene 3,20 dione) was added;the higher fractal dimension corresponds to the higher conversion rate of steroid biotransformation.And the maximum of fractal dimension appeared prior to the maximum of biomass concentration.It is therefore possible to utilize the fractal dimension curve to supervise the fermentation process more timely and availably than to use the conventional biomass curve to do. 展开更多
关键词 metarrhizium anisopliae MORPHOLOGY GROWTH fractal dimension BIOTRANSFORMATION STEROID
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Microstructure evolution and dislocation configurations in nanostructured Al-Mg alloys processed by high pressure torsion 被引量:3
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作者 刘满平 蒋婷慧 +3 位作者 谢学锋 刘强 李雪峰 Hans J.ROVEN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第12期3848-3857,共10页
Microstructure evolution and dislocation configurations in nanostructured Al–Mg alloys processed by high pressure torsion (HPT) were analyzed by transmission electron microscopy (TEM) and high-resolution TEM (HR... Microstructure evolution and dislocation configurations in nanostructured Al–Mg alloys processed by high pressure torsion (HPT) were analyzed by transmission electron microscopy (TEM) and high-resolution TEM (HRTEM). The results show that the grains less than 100 nm have sharp grain boundaries (GBs) and are completely free of dislocations. In contrast, a high density of dislocation as high as 1017 m^-2 exists within the grains larger than 200 nm and these larger grains are usually separated into subgrains and dislocation cells. The dislocations are 60° full dislocations with Burgers vectors of 1/2〈110〉and most of them appear as dipoles and loops. The microtwins and stacking faults (SFs) formed by the Shockley partials from the dissociation of both the 60° mixed dislocation and 0° screw dislocation in ultrafine grains were simultaneously observed by HRTEM in the HPT Al–Mg alloys. These results suggest that partial dislocation emissions, as well as the activation of partial dislocations could also become a deformation mechanism in ultrafine-grained aluminum during severe plastic deformation. The grain refinement mechanism associated with the very high local dislocation density, the dislocation cells and the non-equilibrium GBs, as well as the SFs and microtwins in the HPT Al-Mg alloys were proposed. 展开更多
关键词 Al-Mg aluminum alloy severe plastic deformation high pressure torsion dislocation configurations grain refinement deformation mechanism
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Immunopotentiating Effects of Cucurbitacin B in Mice
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作者 刘颖菊 刘文清 《Journal of Chinese Pharmaceutical Sciences》 CAS 1993年第2期121-126,共6页
Cucurbitacin B(CUB)is a major active principle contained in the calyx melo of Cucumis melo L.The immunopotentiating effects of CuB(im,qd×5)were studied.At lower doses, CuB increased the number of peripheral blood... Cucurbitacin B(CUB)is a major active principle contained in the calyx melo of Cucumis melo L.The immunopotentiating effects of CuB(im,qd×5)were studied.At lower doses, CuB increased the number of peripheral blood T lymphocytes(0.1 mg/kg),the rate of PHA-induced lymphocyte transformation(0.2 mg/kg),the number of plaque forming cells(PFC)of the spleen(0.2 mg/kg)and the level of serum hemolysin(0.4 mg/kg).The phagocytosis of macrophages and the clearance rate of charcoal particles were enhanced only by a large dose(0.8 mg/kg).The results indicate that CuB can potentiate both cellular and humoral immune function. 展开更多
关键词 Cucurbitacin B MACROPHAGE HEMOLYSIN Plaque forming cell Lymphocyte transformation T lymphocyte
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Transformation and Availability of Various Forms of Zinc in Soils 被引量:2
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作者 ZOUBANG-JI MORUN-CANG 《Pedosphere》 SCIE CAS CSCD 1993年第1期35-44,共10页
The transformation and availability of various forms of Zn applied into a cinnamon soil and a carbonate meadow soil as well as the effects of fertilizer-P on them were studied by using the field experiment method and ... The transformation and availability of various forms of Zn applied into a cinnamon soil and a carbonate meadow soil as well as the effects of fertilizer-P on them were studied by using the field experiment method and chemically sequential extraction procedure. Zn added into the soils was found to be rapidly transformed into the various forms. In the cinnamon soil, the amount of Zn transformed into the carbonate bound form was the highest, and the carbonate bound form was proven by the analyses of intensity factor and capacity factor to be the primary available Zn pool.But in the carbonate meadow soil, the Zn transformed was relatively homogeneously distributed in the various forms though the amount of Zn transformed into the Mn-oxide bound form was relatively high, and the organically bound, Mn-oxide bound and amorphous Fe-oxide.bound forms were found to be the main available Zn pool. Fertilizer-P took part in the regulation and control of available Zn in the soils to a certain degree. In the carbonate meadow soil, application of P fertilizer probably aggravated Zn deficiency at low Zn rate, while it was favorable to the storage of available Zn in the case of high Zn rate. 展开更多
关键词 capacity factor carbonate meadow soil cinnamon soil intensity factor P effect
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Estimation of deformed laser heat sources and thermal analysis on laser assisted turning of square member 被引量:2
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作者 KIM Jae-hyun KIM Kwang-sun +1 位作者 CHOI Jun-young LEE Choon-man 《Journal of Central South University》 SCIE EI CAS 2012年第2期402-407,共6页
Laser assisted machining (LAM) has difficulties in estimating temperature after applying a LAM process due to its very small heat input area, large energy and movement. In particular, in the case of laser assisted t... Laser assisted machining (LAM) has difficulties in estimating temperature after applying a LAM process due to its very small heat input area, large energy and movement. In particular, in the case of laser assisted turning (LAT) process, it is more difficult to estimate the temperature after preheating because it has a shape of ellipse when a laser heat source is rotated. A prediction method and thermal analysis method for heat source shapes were proposed as a square shaped member was preheated. The temperature distribution was calculated according to the rotation of the member. Compared with the results of the former study, the maximum temperature of the calculation results, 1 407.1 ℃, is 8.5 ℃ higher than that of the square member, which is 1 398.6 ℃. In a LAT process for a square member, the maximum temperature is 1 850.8 ℃. It is recognized that a laser power control process is required because square members show a maximum temperature that exceeds a melting temperature at around a vertex of the member according to the rotation. 展开更多
关键词 laser assisted machining laser assisted turning laser preheating laser power control
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Effects of organic acids on heavy metal release or immobilization in contaminated soil 被引量:4
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作者 Wen-bin YAO Lei HUANG +1 位作者 Zhi-hui YANG Fei-ping ZHAO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第4期1277-1289,共13页
In order to explicit the environmental activity of heavy metals affected by different organic acids in soil,a batch incubation experiment was explored to investigate the influence of high relative molecular mass organ... In order to explicit the environmental activity of heavy metals affected by different organic acids in soil,a batch incubation experiment was explored to investigate the influence of high relative molecular mass organic acid(HMWOA)(humic acid and fulvic acid)and low relative molecular mass organic acid(LMWOA)(threonic acid and oxalic acid)on the release or immobilization of Pb,Cu and Cd in soils.Results showed that LMWOA,especially threonic acid,had a good performance in the release of Pb,Cu and Cd from soils,and decrease in the fractions of HOAc-extractable,reducible and oxidable Pb,Cu and Cd.Conversely,HMWOA,especially humic acid,decreased the release of Pb,Cu and Cd,while it increased the fractions of HOAc-extractable,reducible and oxidable Pb,Cu and Cd,indicating that HMWOA can immobilize heavy metals.The release of Pb,Cu and Cd caused by LMWOA was attributed to the dissociation of soil organic matter and amorphous iron oxides since the total organic carbon and the water-soluble iron increased.The immobilization of Pb,Cu and Cd by HMWOA was attributed to the adsorption onto HMWOA followed by amorphous iron since HMWOA resulted in a significant decrease of zeta potential and an increase of amorphous iron oxide.It can be concluded that LMWOA has a potential application in soil washing remediation,while HMWOA can be used in the immobilization remediation for heavy metals contaminated soils. 展开更多
关键词 low relative molecular mass organic acid humic acid fulvic acid soil remediation fractionation transformation of heavy metals
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Electromagnetic Model and Image Reconstruction Algorithms Based on EIT System 被引量:3
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作者 曹章 王化祥 《Transactions of Tianjin University》 EI CAS 2006年第6期420-424,共5页
An intuitive 2D model of circular electrical impedance tomography (EIT) sensor with small size electrodes is established based on the theory of analytic functions. The validation of the model is proved using the res... An intuitive 2D model of circular electrical impedance tomography (EIT) sensor with small size electrodes is established based on the theory of analytic functions. The validation of the model is proved using the result from the solution of Laplace equation. Suggestions on to electrode optimization and explanation to the ill-condition property of the sensitivity matrix are provided based on the model, which takes electrode distance into account and can be generalized to the sensor with any simple connected region through a conformal transformation. Image reconstruction algorithms based on the model are implemented to show feasibility of the model using experimental data collected from the EIT system developed in Tianjin University. In the simulation with a human chestlike configuration, electrical conductivity distributions are reconstructed using equi-potential backprojection (EBP) and Tikhonov regularization (TR) based on a conformal transformation of the model. The algorithms based on the model are suitable for online image reconstruction and the reconstructed results are aood both in size and position. 展开更多
关键词 electrical impedance tomography electromagnetic model conformal transformation reconstruction algorithm
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Recent Progress in Cartilage Tissue Engineering--Our Experience and Future Directions 被引量:10
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作者 Yu Liu Guangdong Zhou Yilin Cao 《Engineering》 SCIE EI 2017年第1期28-35,共8页
Given the limited spontaneous repair that follows cartilage injury, demand is growing for tissue engi- neering approaches for cartilage regeneration. There are two major applications for tissue-engineered cartilage. O... Given the limited spontaneous repair that follows cartilage injury, demand is growing for tissue engi- neering approaches for cartilage regeneration. There are two major applications for tissue-engineered cartilage. One is in orthopedic surgery, in which the engineered cartilage is usually used to repair cartilage defects or loss in an articular joint or meniscus in order to restore the joint function. The other is for head and neck reconstruction, in which the engineered cartilage is usually applied to repair cartilage defects or loss in an auricle, trachea, nose, larynx, or eyelid. The challenges faced by the engineered car- tilage for one application are quite different from those faced by the engineered cartilage for the other application. As a result, the emphases of the engineering strategies to generate cartilage are usually quite different for each application. The statuses of preclinical animal investigations and of the clinical translation of engineered cartilage are also at different levels for each application. The aim of this review is to provide an opinion piece on the challenges, current developments, and future directions for cartilage engineering for both applications. 展开更多
关键词 Cartilage tissue engineering Preclinical immunocompetent animal investigation Clinical translation Orthopedic surgery Head and neck reconstruction
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Management of neuroendocrine carcinomas of the pancreas (WHO G3): A tailored approach between proliferation and morphology 被引量:4
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作者 Stefano Crippa Stefano Partelli +7 位作者 Giulio Belfiori Marco Palucci Francesca Muffatti Olga Adamenko Luca Cardinali Claudio Doglioni Giuseppe Zamboni Massimo Falconi 《World Journal of Gastroenterology》 SCIE CAS 2016年第45期9944-9953,共10页
Neuroendocrine carcinomas(NEC) of the pancreas are defined by a mitotic count > 20 mitoses/10 high power fields and/or Ki67 index > 20%, and included all the tumors previously classified as poorly differentiated... Neuroendocrine carcinomas(NEC) of the pancreas are defined by a mitotic count > 20 mitoses/10 high power fields and/or Ki67 index > 20%, and included all the tumors previously classified as poorly differentiated endocrine carcinomas. These latter are aggressive malignancies with a high propensity for distant metastases and poor prognosis, and they can be further divided into small- and large-cell subtypes. However in the NEC category are included also neuroendocrine tumors with a well differentiated morphology but ki67 index > 20%. This category is associated with better prognosis and does not significantly respond to cisplatin-based chemotherapy, which represents the gold standard therapeutic approach for poorly differentiated NEC. In this review, the differences between well differentiated and poorly differentiated NEC are discussed considering both pathology, imaging features, treatment and prognostic implications. Diagnostic and therapeutic flowcharts are proposed. The need for a revision of current classification system is stressed being well differentiated NEC a more indolent disease compared to poorly differentiated tumors. 展开更多
关键词 Pancreatic neuroendocrine tumors Surgery Neuroendocrine carcinomas Chemotherapy Prognosis METASTASES MORPHOLOGY PROLIFERATION
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Species Transformation of Trace Elements and Their Distribution Prediction in Dyestuff Residue Incineration 被引量:4
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作者 谭中欣 李海滨 +2 位作者 王小亮 蒋旭光 严建华 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第2期268-275,共8页
The release of heavy metals from the combustion of hazardous wastes is an environmental issue of in-creasing concern.The species transformation characteristics of toxic heavy metals and their distribution are consid-e... The release of heavy metals from the combustion of hazardous wastes is an environmental issue of in-creasing concern.The species transformation characteristics of toxic heavy metals and their distribution are consid-ered to be a complex problem of mechanism.The behavior of hazardous dyestuff residue is investigated in a tubular furnace under the general condition of hazardous waste pyrolysis and gasfication.Data interpretation has been aided by parallel theoretical study based on a thermodynamic equilibrium model based on the principle of Gibbs free en-ergy minimization.The results show that Ni,Zn,Mn,and Cr are more enriched in dyestuff residue incineration than other heavy metals(Hg,As,and Se)subjected to volatilization.The thermodynamic model calculation is used for explaining the experiment data at 800℃ and analyzing species transformation of heavy metals.These results of species transformation are used to predict the distribution and emission characteristics of trace elements.Although most trace element predictions are validated by the measurements,cautions are in order due to the complexity of incineration systems. 展开更多
关键词 hazardous waste INCINERATION thermodynamic equilibrium model heavy metals species transformation PREDICTION
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Tetrandrine inhibits activation of rat hepatic stellate cells in vitro via transforming growth factor-β signaling 被引量:11
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作者 Yuan-WenChen Jian-XinWu Ying-WeiChen Ding-GuoLi Han-MingLu 《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第19期2922-2926,共5页
AIM: To investigate the effect of various concentrations of tetrandrine on activation of quiescent rat hepatic stellate cells (HSCs) and transforming growth factor-β (TGF-β) signaling in vitro.METHODS: HSCs were iso... AIM: To investigate the effect of various concentrations of tetrandrine on activation of quiescent rat hepatic stellate cells (HSCs) and transforming growth factor-β (TGF-β) signaling in vitro.METHODS: HSCs were isolated from rats by in situperfusion of liver and 18% Nycodenz gradient centrifugation, and primarily cultured on uncoated plastic plates for 24 hwith DMEM containing 20% fetal bovine serum (FBS/DMEM) before the culture medium was substituted with 2% FBS/DMEM for another 24 h. Then, the HSCs were cultured in 2% FBS/DMEM with tetrandrine (0.25, 0.5, 1,2 mg/L, respectively). Cell morphological features were observed under an inverted microscope, smooth muscleα-actin (α-SMA) was detected by immunocytochemistry and image analysis system, laminin (LN) and type Ⅲprocollagen (PCⅢ) in supernatants were determined byradioimmunoassay. TGF-β1 mRNA, Smad 7 mRNA and Smad 7 protein were analyzed with RT-PCR and Western blotting, respectively.RESULTS: Tetrandrine at the concentrations of 0.25-2 mg/L prevented morphological transformation of HSC from the quiescent state to the activated one, while α-SMA, LN and PCⅢ expressions were inhibited. As estimated by gray values, the expression of α-SMA in tetrandrine groups (0.25, 0.5, 1, 2 mg/L) was reduced from 21.3% to 42.2%(control: 0.67, tetrandrine groups: 0.82, 0.85, 0.96, or 0.96, respectively, which were statistically different from the control, P<0.01), and the difference was more significant in tetrandrine at 1 and 2 mg/L. The content of LN in supernatants was significantly decreased in tetrandrine groups to 58.5%, 69.1%, 65.8% or 60.0% that of the control respectively, and that of PCⅢ to 84.6%, 81.5%,75.7% or 80.7% respectively (P<0.05 vs control), with no significant difference among tetrandrine groups. RTPCR showed that TGF-β1 mRNA expression was reduced by tetrandrine treatments from 56.56% to 87.90% in comparison with the control, while Smad 7 mRNA was increased 1.4-4.8 times. The TGF-β1 mRNA and Smad 7 mRNA expression was in a significant negative correlation (r= -0.755, P<0.01), and both were significantly correlated with α-SMA protein expression (r = -0.938, P<0.01;r = 0.938, P<0.01, respectively). The up-regulation of Smad 7 protein by tetrandrine (1 mg/L)was confirmed by Western blotting as well.CONCLUSION: Tetrandrine has a direct inhibiting effect on the activation of rat HSCs in culture. It up-regulates the expression of Smad 7 which in turn blocks TGF-β1 expression and signaling. 展开更多
关键词 TETRANDRINE Hepatic stellate cell Transforming growth factor-β Smad 7 Liver fibrosis Signal transduction
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