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Diagnostic value of PIVKA-Ⅱ and alpha-fetoprotein in hepatitis B virus-associated hepatocellular carcinoma 被引量:65
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作者 Seung In Seo Hyoung Su Kim +10 位作者 Won Jin Kim Woon Geon Shin Doo Jin Kim Kyung Ho Kim Myoung Kuk Jang Jin Heon Lee Joo Seop Kim Hak Yang Kim Dong Joon Kim Myung Seok Lee Choong Kee Park 《World Journal of Gastroenterology》 SCIE CAS 2015年第13期3928-3935,共8页
AIM: To determine the cutoff values and to compare the diagnostic role of alpha-fetoprotein(AFP) and prothrombin induced by vitamin K absence-Ⅱ(PIVKA-Ⅱ) in chronic hepatitis B(CHB).METHODS: A total of 1255 patients ... AIM: To determine the cutoff values and to compare the diagnostic role of alpha-fetoprotein(AFP) and prothrombin induced by vitamin K absence-Ⅱ(PIVKA-Ⅱ) in chronic hepatitis B(CHB).METHODS: A total of 1255 patients with CHB, including 157 patients with hepatocellular carcinoma(HCC), 879 with non-cirrhotic CHB and 219 with cirrhosis without HCC, were retrospectively enrolled. The areas under the receiver operating characteristic(AUROC) curves of PIVKA-Ⅱ, AFP and their combination were calculated and compared.RESULTS: The optimal cutoff values for PIVKA-Ⅱ and AFP were 40 m AU/m L and 10 ng/m L, respectively, for the differentiation of HCC from nonmalignant CHB. The sensitivity and specificity were 73.9% and 89.7%, respectively, for PIVKA-Ⅱ and 67.5% and 90.3% for AFP, respectively. The AUROC curves of both PIVKA-Ⅱ and AFP were not significantly different(0.854 vs 0.853, P = 0.965) for the differentiation of HCC from nonmalignant CHB, whereas the AUROC of PIVKA-Ⅱ was significantly better than that of AFP in patients with cirrhosis(0.870 vs 0.812, P = 0.042). When PIVKA-Ⅱ and AFP were combined, the diagnostic power improved significantly compared to either AFP or PIVKA-Ⅱ alone for the differentiation of HCC from nonmalignant CHB(P < 0.05), especially when cirrhosis was present(P < 0.05).CONCLUSION: Serum PIVKA-Ⅱ might be a better tumor marker than AFP, and its combination with AFP may enhance the early detection of HCC in patients with CHB. 展开更多
关键词 HEPATITIS B VIRUS HEPATOCELLULAR CARCINOMA alpha-f
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纳米铁微粒表面氧化物的结构及磁性 被引量:22
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作者 赵新清 梁勇 胡壮麒 《金属学报》 SCIE EI CAS CSCD 北大核心 2001年第6期633-636,共4页
用激光气相热解法制备了α-Fe(bcc)和γ-Fe(fcc)纳米微粒利用高分辨透射电子显微镜、X射线衍射和磁测量研究了纳米微粒表面氧化物的结构、形貌及磁性能结果表明,纳米铁微粒表面的氧化铁厚度约5nm;由细小微晶(2... 用激光气相热解法制备了α-Fe(bcc)和γ-Fe(fcc)纳米微粒利用高分辨透射电子显微镜、X射线衍射和磁测量研究了纳米微粒表面氧化物的结构、形貌及磁性能结果表明,纳米铁微粒表面的氧化铁厚度约5nm;由细小微晶(2-5nm)组成.该氧化铁层呈非铁磁或超顺磁性.室温下微粒表面形成的氧化铁为FeO4,而非Fe3O4和α-Fe2O3的混合物。 展开更多
关键词 纳米微粒 氧化铁 磁性能 结构
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H_2+H_2O还原法制备超细金属磁记录粉 被引量:4
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作者 王其祥 宋宝珍 李洪钟 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2001年第5期861-866,共6页
采用H2+H2O还原法,通过控制H2O/H2比可改善粉体晶粒链状结构的晶间界面结构,采用XRD、TEM、VSM等方法测试粉体的晶体结构、粒子形貌和磁性能.结果为金属磁粉的矫顽力提高;粒子形状均匀,表面平滑,毛刺少;4... 采用H2+H2O还原法,通过控制H2O/H2比可改善粉体晶粒链状结构的晶间界面结构,采用XRD、TEM、VSM等方法测试粉体的晶体结构、粒子形貌和磁性能.结果为金属磁粉的矫顽力提高;粒子形状均匀,表面平滑,毛刺少;460℃时H2+H2O还原金属磁粉的矫顽力为1520Oe,比传统氢还原工艺矫顽力1440Oe提高5.6%.采用流化床反应器,具有温度均匀,气固接触充分,可防止颗粒烧结等优点,工业应用前景广阔. 展开更多
关键词 金属磁记录粉 H2 H2O 还原 晶粒链状结构 氢气 磁性记录材料
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纳米复合永磁材料的交换耦合作用和有效各向异性 被引量:1
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作者 刘丽妹 史艳晶 +3 位作者 聂莉莹 李爱君 胡金江 陈伟 《金属学报》 SCIE EI CAS CSCD 北大核心 2005年第3期317-320,共4页
以Nd2Fe14B/α-Fe为例,对纳米双相永磁材料软、硬磁性相晶粒间的交换耦合作用和有效各向异性进行了模型化计 算,得到软、硬磁性相晶粒间的有效各向异性常数随晶粒尺寸和软磁性相比例的变化关系曲线.结果表明,交换耦合部分采用6种 不同... 以Nd2Fe14B/α-Fe为例,对纳米双相永磁材料软、硬磁性相晶粒间的交换耦合作用和有效各向异性进行了模型化计 算,得到软、硬磁性相晶粒间的有效各向异性常数随晶粒尺寸和软磁性相比例的变化关系曲线.结果表明,交换耦合部分采用6种 不同函数计算,得到的有效各向异性随晶粒尺寸的变化曲线几乎重合.有效各向异性常数随晶粒尺寸的减小逐渐减小,随软磁性相 比例的减小逐渐增大. 展开更多
关键词 Nd—Ee—B/α—Ee 纳米复合材料 凝固物理 交换耦合作用 有效各向异性
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Stereoselective Synthesis of (Z)-2-Acylamido-4-phenylcrotonates
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作者 Yi Nong XIE Fan Min FU +1 位作者 Ai Qiao MI Yao Zhong JIANG(Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences,Chengdu 610041) 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第7期567-570,共4页
Two practical methods for highly stereoselective synthesis of (Z)-2-acylamido-4-phenylcrotonates 2a similar to b have been developed. The key step in the first route was how to control the acid-catalyzed isomerization... Two practical methods for highly stereoselective synthesis of (Z)-2-acylamido-4-phenylcrotonates 2a similar to b have been developed. The key step in the first route was how to control the acid-catalyzed isomerization of condensation mixtures of alpha-keto ester 5 with carbomite. In the second route the key step was reduction of oxime 8, derived from alpha-keto ester 5, with iron powder in the presence of acetic anhydride. 展开更多
关键词 (Z)-alpha beta-dehydroamino acids stereoselective synthesis E -> Z isomerization Fe/Ac2O reduction of oxime
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