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PartLabeling:A label management framework in 3D space
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作者 Semir ELEZOVIKJ Jianqing JIA +1 位作者 Chiu CTAN Haibin LING 《Virtual Reality & Intelligent Hardware》 EI 2023年第6期490-508,共19页
Background In this work,we focus on the label layout problem:specifying the positions of overlaid virtual annotations in Virtual/Augmented Reality scenarios.Methods Designing a layout of labels that does not violate d... Background In this work,we focus on the label layout problem:specifying the positions of overlaid virtual annotations in Virtual/Augmented Reality scenarios.Methods Designing a layout of labels that does not violate domain-specific design requirements,while at the same time satisfying aesthetic and functional principles of good design,can be a daunting task even for skilled visual designers.Presenting the annotations in 3D object space instead of projection space,allows for the preservation of spatial and depth cues.This results in stable layouts in dynamic environments,since the annotations are anchored in 3D space.Results In this paper we make two major contributions.First,we propose a technique for managing the layout and rendering of annotations in Virtual/Augmented Reality scenarios by manipulating the annotations directly in 3D space.For this,we make use of Artificial Potential Fields and use 3D geometric constraints to adapt them in 3D space.Second,we introduce PartLabeling:an open source platform in the form of a web application that acts as a much-needed generic framework allowing to easily add labeling algorithms and 3D models.This serves as a catalyst for researchers in this field to make their algorithms and implementations publicly available,as well as ensure research reproducibility.The PartLabeling framework relies on a dataset that we generate as a subset of the original PartNet dataset consisting of models suitable for the label management task.The dataset consists of 10003D models with part annotations. 展开更多
关键词 label layout 3D object space labels
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基于衍生化3-氨基-2-恶唑烷酮的夹心酶联免疫分析
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作者 张世伟 吴会玲 +6 位作者 周迎春 王炳志 杨星星 杜业刚 汤璐 冯荣虎 郭继平 《食品科学》 EI CAS CSCD 北大核心 2024年第6期271-276,共6页
建立一种3-氨基-2-恶唑烷酮(3-amino-2-oxazolidinone,AOZ)夹心免疫检测方法。通过1,6-己二醇连接2-硝基-4-羧基苯甲醛和生物素合成针对AOZ的新型衍生试剂。在样品前处理时加入衍生试剂可对AOZ进行衍生,衍生产率为89%。在酶标板上包被抗... 建立一种3-氨基-2-恶唑烷酮(3-amino-2-oxazolidinone,AOZ)夹心免疫检测方法。通过1,6-己二醇连接2-硝基-4-羧基苯甲醛和生物素合成针对AOZ的新型衍生试剂。在样品前处理时加入衍生试剂可对AOZ进行衍生,衍生产率为89%。在酶标板上包被抗AOZ单克隆抗体并以辣根过氧化物酶标记的亲和素或抗生物素抗体作为第二结合物可实现AOZ的夹心酶联免疫吸附检测(enzyme-linked immunosorbnent assay,ELISA)。从实际应用的角度,得到双抗夹心和抗体-亲和素夹心模式下两个表位的极限距离,分别为12Å和13Å,理想距离分别为16Å和17Å。在双抗夹心和抗体-亲和素夹心模式下的检出限分别达到1.8 pg/mL和0.8 pg/mL(以AOZ质量浓度计),相对于竞争ELISA,其灵敏度最高提高了25倍。平均回收率为73%~85%,平均相对标准偏差为9.0%。 展开更多
关键词 3-氨基-2-恶唑烷酮 夹心酶联免疫分析 表位间隔距离 辣根过氧化物酶标记亲和素
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达比加群酯-d_(3)的合成 被引量:1
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作者 王昌 梁林辉 +2 位作者 姚永秀 梁大伟 董金华 《化学试剂》 CAS 2024年第1期105-110,共6页
研究抗凝血药物达比加群酯-d_(3)的合成工艺。以4-氯-3-硝基苯甲酸甲酯为起始原料,氘代甲胺盐酸盐为氘代试剂,经氘代甲基化、取代、还原、缩合、环合、水解、亲核等反应得到关键氘化中间体3-{[(2-{[(4-氰基苯基)氨基]甲基}-1-(甲基-d_(... 研究抗凝血药物达比加群酯-d_(3)的合成工艺。以4-氯-3-硝基苯甲酸甲酯为起始原料,氘代甲胺盐酸盐为氘代试剂,经氘代甲基化、取代、还原、缩合、环合、水解、亲核等反应得到关键氘化中间体3-{[(2-{[(4-氰基苯基)氨基]甲基}-1-(甲基-d_(3))苯并咪唑-5-基)氧亚基](吡啶-2-基)氨基}丙酸乙酯,而后再经氨解和亲核反应,成功制备稳定的达比加群酯-d_(3),8步反应总产率为6.4%,目标化合物结构经NMR和MS确认,同位素丰度达99.7%。该合成方法原料简单易得、操作简便、重现性好,可用于达比加群酯-d_(3)的合成。 展开更多
关键词 抗凝血药物 达比加群酯-d_(3) 合成工艺 优化 同位素标记
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不超过7阶的3-关系图的刻画
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作者 黄茹雅 龙旸靖 詹鹏锦 《华中师范大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第2期159-164,共6页
给定一个图G,如果存在一个边标号树T,使得树T的叶子集等于图G的顶点集,并且树T任何叶子x到叶子y的唯一路径上的边标号之和为3当且仅当xy为图G的边,那么称图G是一个3-关系图.该文讨论了什么样的图是3-关系图,证明了图G是3-关系图的必要... 给定一个图G,如果存在一个边标号树T,使得树T的叶子集等于图G的顶点集,并且树T任何叶子x到叶子y的唯一路径上的边标号之和为3当且仅当xy为图G的边,那么称图G是一个3-关系图.该文讨论了什么样的图是3-关系图,证明了图G是3-关系图的必要条件为图G是二部图,即只要图G包含奇圈,则图G不是3-关系图.更进一步,完全刻画了圈为3-关系图的充要条件,即一个圈是3-关系图当且仅当圈为偶圈,并且给出了偶圈相对应的边标号树.最后讨论了比较小的图为3-关系图的条件,即证明了阶至多为7的图是3-关系图的充分必要条件为图G是二部图. 展开更多
关键词 3-关系图 边标号树 二部图
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The L(3,2,1)-labeling on Bipartite Graphs
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作者 YUAN WAN-LIAN ZHAI MING-QING Lǔ CHANG-HONG 《Communications in Mathematical Research》 CSCD 2009年第1期79-87,共9页
An L(3, 2, 1)-labeling of a graph G is a function from the vertex set V(G) to the set of all nonnegative integers such that |f(u)-f(v)|≥3 if dG(u,v) = 1, |f(u)-f(v)|≥2 if dG(u,v) = 2, and |f(u... An L(3, 2, 1)-labeling of a graph G is a function from the vertex set V(G) to the set of all nonnegative integers such that |f(u)-f(v)|≥3 if dG(u,v) = 1, |f(u)-f(v)|≥2 if dG(u,v) = 2, and |f(u)-f(v)|≥1 if dG(u,v) = 3. The L(3, 2,1)-labeling problem is to find the smallest number λ3(G) such that there exists an L(3, 2,1)-labeling function with no label greater than it. This paper studies the problem for bipartite graphs. We obtain some bounds of λ3 for bipartite graphs and its subclasses. Moreover, we provide a best possible condition for a tree T such that λ3(T) attains the minimum value. 展开更多
关键词 channel assignment problems L(2 1)-labeling L(3 2 1)-labeling bi-partite graph TREE
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Three-dimensional arterial spin labeling and diffusion kurtosis imaging in evaluating perfusion and infarct area size in acute cerebral ischemia 被引量:3
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作者 Yan-Yan Jiang Zhi-Lin Zhong Min Zuo 《World Journal of Clinical Cases》 SCIE 2022年第17期5586-5594,共9页
BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 h.Therefore,early diagnosis and evaluation of cerebral infarction is imp... BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 h.Therefore,early diagnosis and evaluation of cerebral infarction is important.AIM To investigate the diagnostic value of magnetic resonance multi-delay threedimensional arterial spin labeling(3DASL)and diffusion kurtosis imaging(DKI)in evaluating the perfusion and infarct area size in patients with acute cerebral ischemia.METHODS Eighty-four patients who experienced acute cerebral ischemia from March 2019 to February 2021 were included.All patients in the acute stage underwent magnetic resonance-based examination,and the data were processed by the system’s own software.The apparent diffusion coefficient(ADC),average diffusion coefficient(MD),axial diffusion(AD),radial diffusion(RD),average kurtosis(MK),radial kurtosis(fairly RK),axial kurtosis(AK),and perfusion parameters post-labeling delays(PLD)in the focal area and its corresponding area were compared.The correlation between the lesion area of cerebral infarction under MK and MD and T2-weighted imaging(T2WI)was analyzed.RESULTS The DKI parameters of focal and control areas in the study subjects were compared.The ADC,MD,AD,and RD values in the lesion area were significantly lower than those in the control area.The MK,RK,and AK values in the lesion area were significantly higher than those in the control area.The MK/MD value in the infarct lesions was used to determine the matching situation.MK/MD<5 mm was considered matching and MK/MD≥5 mm was considered mismatching.PLD1.5s and PLD2.5s perfusion parameters in the central,peripheral,and control areas of the infarct lesions in MK/MD-matched and-unmatched patients were not significantly different.PLD1.5s and PLD2.5s perfusion parameter values in the central area of the infarct lesions in MK/MD-matched and-unmatched patients were significantly lower than those in peripheral and control areas.The MK and MD maps showed a lesion area of 20.08±5.74 cm^(2) and 22.09±5.58 cm^(2),respectively.T2WI showed a lesion area of 19.76±5.02 cm^(2).There were no significant differences in the cerebral infarction lesion areas measured using the three methods.MK,MD,and T2WI showed a good correlation.CONCLUSION DKI parameters showed significant difference between the focal and control areas in patients with acute ischemic cerebral infarction.3DASL can effectively determine the changes in perfusion levels in the lesion area.There was a high correlation between the area of the infarct lesions diagnosed by DKI and T2WI. 展开更多
关键词 Magnetic resonance Multi-delay 3D arterial spin labeling Diffusion kurtosis imaging Acute ischemic cerebral infarction PERFUSION Nerve function
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CATALYTIC LABELLING AND ~3H NMR ANALYSES OF SOME AROMATIC AND HETEROCYCLIC COMPOUNDS
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作者 张丽明 John R. Jones 《Nuclear Science and Techniques》 SCIE CAS CSCD 1991年第3期184-189,共6页
This paper described the ~3H NMR determination of the positions and content of 24 tritium labeled aromatic and heterocyclic compounds prepared by catalytic tritiation derivatives, pyrrole, 1,2,4-triazole, thiazole, be... This paper described the ~3H NMR determination of the positions and content of 24 tritium labeled aromatic and heterocyclic compounds prepared by catalytic tritiation derivatives, pyrrole, 1,2,4-triazole, thiazole, benzothiazole, purine and derivatives, indole, indanol, piperidine and derivative, diphenylamine, N- phenylanthranilic acid, 8- OH- quinoline, naphthol, diphenylether have been tritiated by catalytic exchange method using tritiated water and platinum catalyst (from the dioxide and sodium borohydride), and the pattern of labelling has been assigned by ~3H NMR spectroscopy. The results show that this exchange process can give general labelling compounds at various time and temperatures. For 4-Br-diphenylether, Raney nickel was used instead of Pt as a catalyst. 展开更多
关键词 ~3H NMR labeled HETEROCYCLIC COMPOUNDS AROMATIC CATALYTIC labelling
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Ultralow detection limit of giant magnetoresistance biosensor using Fe3O4–graphene composite nanoparticle label
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作者 徐洁 焦吉庆 +1 位作者 李强 李山东 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第1期151-155,共5页
A special Fe3O4nanoparticles–graphene(Fe3O4–GN) composite as a magnetic label was employed for biodetection using giant magnetoresistance(GMR) sensors with a Wheatstone bridge. The Fe3O4–GN composite exhibits a... A special Fe3O4nanoparticles–graphene(Fe3O4–GN) composite as a magnetic label was employed for biodetection using giant magnetoresistance(GMR) sensors with a Wheatstone bridge. The Fe3O4–GN composite exhibits a strong ferromagnetic behavior with the saturation magnetization MS of approximately 48 emu/g, coercivity HC of 200 Oe, and remanence Mr of 8.3 emu/g, leading to a large magnetic fringing field. However, the Fe3O4 nanoparticles do not aggregate together, which can be attributed to the pinning and separating effects of graphene sheet to the magnetic particles. The Fe3O4–GN composite is especially suitable for biodetection as a promising magnetic label since it combines two advantages of large fringing field and no aggregation. As a result, the concentration x dependence of voltage difference |?V| between detecting and reference sensors undergoes the relationship of |?V| = 240.5 lgx + 515.2 with an ultralow detection limit of 10 ng/mL(very close to the calculated limit of 7 ng/mL) and a wide detection range of 4 orders. 展开更多
关键词 giant magnetoresistance biosensors magnetic label Fe3O4–graphene composite lowest detection limit
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基于体素的形态学测量结合ASL在脊髓小脑共济失调3型诊断中的应用价值
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作者 胡曼诗 初建平 +3 位作者 丘海珊 吴超 黄子桓 赵静 《影像诊断与介入放射学》 2023年第1期55-60,共6页
目的 探讨基于体素的形态学测量方法 (VBM)结合3D脉冲式动脉自旋标记灌注成像(3D-PASL)对脊髓小脑共济失调3型(SCA3)的诊断价值。方法 前瞻性收集2018年5月~2019年5月经基因检测证实为SCA3的患者,并募集与其性别、年龄、身体质量指数(B... 目的 探讨基于体素的形态学测量方法 (VBM)结合3D脉冲式动脉自旋标记灌注成像(3D-PASL)对脊髓小脑共济失调3型(SCA3)的诊断价值。方法 前瞻性收集2018年5月~2019年5月经基因检测证实为SCA3的患者,并募集与其性别、年龄、身体质量指数(BMI)匹配的健康志愿者。对所有入组者行基于全脑的T1WI磁化强度预备快速梯度回波(T1MPRAGE)和3D-PASL扫描,获得被试者经Dartel配准后的全脑标准化灰质概率图以及全脑脑血流量(CBF)图。进一步通过组间VBM比较确定灰质体积显著差异的脑区及其特利尔神经研究所(MNI)标准空间坐标作为兴趣区,提取相应脑区的CBF值,并通过非参数检验和受试者工作特性曲线(ROC)分析评价其对SCA3的诊断价值。结果 相比健康对照[n=12,平均(36.92±14.26)岁],VBM示SCA3患者[n=19,平均(40.89±13.72)岁]的右侧小脑半球存在灰质体积显著减低区域,主要位于右侧小脑前叶(MNI坐标x:18,y:-54,z:-19.5)(P<0.05,FWE校正)。进一步对比分析相应区域的CBF值,结果表明SCA3患者右侧小脑前叶的CBF值(56.0±30.9) ml/100 g/min明显高于对照组(29.6±21.0)ml/100 g/min(P<0.05)。ROC分析显示,基于右侧小脑前叶的CBF对SCA3具有中等程度的诊断效能,曲线下面积(AUC)为0.75,特异度、敏感度和界值分别为75.0%、84.2%和29.8 ml/100 g/min。结论 相比健康对照,SCA3患者的右侧小脑前叶灰质体积显著减低,相应区域CBF增高。基于右侧小脑前叶的CBF值可用于诊断SCA3。 展开更多
关键词 脊髓小脑共济失调3 基于体素的形态学测量方法 三维脉冲式动脉自旋标记成像 脑血流量
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A parallel pipeline connected-component labeling method for on-orbit space target monitoring
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作者 LI Zongling ZHANG Qingjun +1 位作者 LONG Teng ZHAO Baojun 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2022年第5期1095-1107,共13页
The paper designs a peripheral maximum gray differ-ence(PMGD)image segmentation method,a connected-compo-nent labeling(CCL)algorithm based on dynamic run length(DRL),and a real-time implementation streaming processor ... The paper designs a peripheral maximum gray differ-ence(PMGD)image segmentation method,a connected-compo-nent labeling(CCL)algorithm based on dynamic run length(DRL),and a real-time implementation streaming processor for DRL-CCL.And it verifies the function and performance in space target monitoring scene by the carrying experiment of Tianzhou-3 cargo spacecraft(TZ-3).The PMGD image segmentation method can segment the image into highly discrete and simple point tar-gets quickly,which reduces the generation of equivalences greatly and improves the real-time performance for DRL-CCL.Through parallel pipeline design,the storage of the streaming processor is optimized by 55%with no need for external me-mory,the logic is optimized by 60%,and the energy efficiency ratio is 12 times than that of the graphics processing unit,62 times than that of the digital signal proccessing,and 147 times than that of personal computers.Analyzing the results of 8756 images completed on-orbit,the speed is up to 5.88 FPS and the target detection rate is 100%.Our algorithm and implementation method meet the requirements of lightweight,high real-time,strong robustness,full-time,and stable operation in space irradia-tion environment. 展开更多
关键词 Tianzhou-3 cargo spacecraft(TZ-3) connected-component labeling(CCL)algorithms parallel pipeline processing on-orbit space target detection streaming processor
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Studies on mitochondrial macromolecular syntheses in various organs of aging animals labeled with 3H-precursors as revealed by electron microscopic radioautography
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作者 Tetsuji Nagata 《Advances in Bioscience and Biotechnology》 2010年第4期241-262,共22页
In order to study the aging changes of intramitochondrial macromolecular synthesis in various organs of aging animals during the development and aging, 10 groups of developing and aging mice, each consisting of 3 indi... In order to study the aging changes of intramitochondrial macromolecular synthesis in various organs of aging animals during the development and aging, 10 groups of developing and aging mice, each consisting of 3 individuals, total 30, from fetal day 19 to postnatal newborn at day 1, 3, 9, 14 and adult at month 1, 2, 6, 12 to 24 were injected with 3H-thymidine a DNA precurson, another 10 groups consisting of 3 individuals, total 30, were injected with 3H-uridine a RNA precursor, and another 10 groups of 30 individuals were injected with 3H-leucine a protein precursor, total 90 individuals. Then, all the animals were sacrificed 1 hr after the injections and the liver tissues, the lung tissues, the kidney tissues, the testis and ovary tissues, the adrenal tissues were taken out, fixed and processed for electron microscopic radioautography. On electron microscopic radioautograms obtained from each animal, ten photographs in respective groups, numbers of mitochondria per cell profile area, numbers of labeled mitochondria per cell and the mitochondrial labeling index (LI) labeled with 3H-thymidine showing DNA synthesis, LI labeled with 3H-uridine showing RNA synthesis, and LI labeled with 3H-leucine showing protein synthesis, in various organs, were counted and the results in various organs in respective aging groups were compared, respectively. From the results, it was demonstrated that the numbers of mitochondria in hepatocytes as well as in 3 zones of the adrenal cortex, the zona glomerulosa, fasciculata and reticularis of mice at various ages increased from fetal day 19 to postnatal month 1 due to development and aging of animals. On the other hand, the numbers of labeled mitochondria and the labeling indices of intramitochondrial DNA syntheses incorporating 3H-thymidine in hepatocytes and 3 zones of cortical cells increased from fetal day 19 to postnatal month 1 and decreased to month 24. The numbers of labeled mitochondria and the labeling indices of intramitochondrial RNA syntheses incorporating 3H-uridine in hepatocytes and 3 zones of cortical cells increased from fetal day 19 to postnatal month 1 and decreased to month 24. The numbers of labeled mitochondria and the labeling indices of intramitochondrial RNA syntheses incorporating 3H-uridine in hepatocytes and 3 ones of cortical cells increased from fetal day 19 to postnatal month 1 and decreased to month 24. Moreover, some other organs such as the lung and the testis were also review and discussed. From the results, it was shown that the activity of intramitochnodrial DNA synthesis, RNA synthesis, and protein synthesis in hepatocytes, adrenal cortical cells, pulmonary cells and testicular cells in developing and aging mice as well as some other organs increased and decreased due to development and aging. 展开更多
关键词 MITOCHONDRIAL Macromolecular SYNTHESES AGING ANIMALS labeled 3H-Precursors ELECTRON MICROSCOPIC Radioautography
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稳定同位素氘标记左氧氟沙星-D_(3)的合成 被引量:1
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作者 徐仲杰 张立 +2 位作者 孙雯 张鹏帅 雷雯 《同位素》 CAS 2023年第2期144-149,I0002,共7页
为了提高稳定同位素利用率,建立简便、成本低廉的合成方法,本研究以哌嗪为起始原料,和氯甲酸苄酯(CBZ-Cl)反应得到CBZ-哌嗪,然后与碘甲烷-D_(3)反应得到CBZ-哌嗪-CD_(3),之后脱去CBZ保护得到甲基哌嗪-D_(3),最后和左氧氟沙星羧酸反应得... 为了提高稳定同位素利用率,建立简便、成本低廉的合成方法,本研究以哌嗪为起始原料,和氯甲酸苄酯(CBZ-Cl)反应得到CBZ-哌嗪,然后与碘甲烷-D_(3)反应得到CBZ-哌嗪-CD_(3),之后脱去CBZ保护得到甲基哌嗪-D_(3),最后和左氧氟沙星羧酸反应得到左氧氟沙星-D_(3)。以投入的碘甲烷-D_(3)物质的量计算,左氧氟沙星-D_(3)产率为37.0%。所合成的左氧氟沙星-D_(3)产品经核磁共振波谱、高效液相色谱和质谱等表征确认,化学纯度为98.5%,同位素丰度为99.5atom%D,以上结果表明,合成的左氧氟沙星-D_(3)可作为同位素内标用于动物源食品中左氧氟沙星残留的定量检测。 展开更多
关键词 稳定同位素标记 左氧氟沙星-D_(3) 内标试剂
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3~6岁幼儿面部表情识别与标签的发展特点 被引量:22
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作者 王振宏 田博 +1 位作者 石长地 崔雪融 《心理科学》 CSSCI CSCD 北大核心 2010年第2期325-328,285,共5页
随机选取幼儿园托儿班、小、中、大班幼儿各一个班,共130名幼儿为被试,运用从Matsumoto和Ekman编制的面部表情图片(JACFEE)中选取的36张,让3~6岁幼儿分别进行识别和标签,探讨了3~6岁幼儿面部表情识别与标签的发展特点。结果发现:(1)... 随机选取幼儿园托儿班、小、中、大班幼儿各一个班,共130名幼儿为被试,运用从Matsumoto和Ekman编制的面部表情图片(JACFEE)中选取的36张,让3~6岁幼儿分别进行识别和标签,探讨了3~6岁幼儿面部表情识别与标签的发展特点。结果发现:(1)幼儿最先能够较好识别高兴表情,其次是愤怒、悲伤表情;再次是恐惧、惊奇、厌恶表情。(2)3岁左右幼儿对于6种面部表情均不能正确标签。4~6岁对于高兴、愤怒、悲伤面部表情标签成绩较好,恐惧和惊奇面部表情标签成绩次之,3~6岁各年龄幼儿对于厌恶表情均不能正确标签。(3)3~6岁各年龄幼儿的面部表情识别成绩高于标签成绩,无论是表情识别还是标签3~5岁是一个迅速发展期,5岁以后逐渐达到一个相对稳定的水平。 展开更多
关键词 3~6岁幼儿 面部表情 识别 标签
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利用^(15)NO_3^-标记法研究土壤微生物量氮的化学及生物有效性 被引量:7
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作者 周建斌 李生秀 +1 位作者 陈竹君 赵满兴 《土壤学报》 CAS CSCD 北大核心 2003年第6期888-893,共6页
采用加入含15N的硝态氮培养方法标记了土壤微生物量氮 ,然后利用碱解扩散法测定了标记土壤有效氮含量 ,温室培养法评价了小麦对标记的土壤微生物量氮的吸收情况。结果表明 ,碱解扩散法对土壤微生物量固持的15N的提取比率 (即提取液中15... 采用加入含15N的硝态氮培养方法标记了土壤微生物量氮 ,然后利用碱解扩散法测定了标记土壤有效氮含量 ,温室培养法评价了小麦对标记的土壤微生物量氮的吸收情况。结果表明 ,碱解扩散法对土壤微生物量固持的15N的提取比率 (即提取液中15N原子百分超 /土壤15N原子百分超 )在 1 47~ 2 83之间(平均 2 0 1 ) ,碱解氮中约有 3 0 1 %~ 61 6% (平均 42 9% )来自土壤微生物固持氮。植物体15N丰度在0 749%~ 1 1 62 %之间 ,明显高于15N的自然丰度 ,表明土壤微生物固持的15N在小麦生长期间发生释放 ,为植物利用。土壤微生物固持氮对植物的有效性比率 (植物地上部分15N原子百分超 /土壤15N原子百分超 )在 3 7~ 7 1之间。可见 。 展开更多
关键词 ^15NO3^-标记法 土壤微生物量氮 化学有效性 生物有效性
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全脑3D-ASL和SWI联合检查在急性大面积脑梗死治疗中的价值 被引量:21
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作者 张国伟 陈锋 +5 位作者 李忠维 王爱杰 梁辉 王英 任金岩 张光辉 《医学影像学杂志》 2016年第7期1170-1174,共5页
目的 探讨3D-ASL和SWI技术对急性大面积脑梗死治疗方案的指导价值。方法 回顾性分析46例急性大面积脑梗死患者在治疗前后的ASL和SWI表现,其中4例于治疗前、4例于动脉溶栓治疗后、5例静脉溶栓治疗后、33例抗凝治疗后、12例于治疗后30~60... 目的 探讨3D-ASL和SWI技术对急性大面积脑梗死治疗方案的指导价值。方法 回顾性分析46例急性大面积脑梗死患者在治疗前后的ASL和SWI表现,其中4例于治疗前、4例于动脉溶栓治疗后、5例静脉溶栓治疗后、33例抗凝治疗后、12例于治疗后30~60天复查,根据治疗方案的不同,分别统计急性大面积脑梗死患者ASL像高/低灌注、SWI像出血或侧枝循环形成的影像学表现,按NIHSS评分评价临床愈后效果。结果 本组46例中,14例患者ASL像上呈局部或大部分高灌注,占30%,其余32例为低灌注,占70%;4例行动脉溶栓,ASL像上呈局部或大部分高灌注,SWI像上均可见面积大小不等的低信号出血灶;5例行静脉溶栓,ASL像上呈高灌注3例、呈低灌注2例,SWI像可见脑出血1例;33例行抗凝治疗,7例于治疗后ASL像上呈高灌注,其中5例SWI像可见低信号出血灶,2例SWI像上未见出血灶;26例ASL像呈低灌注,10例SWI像上可见出血灶,16例SWI像未见出血灶。4例有房颤病史且平常口服抗凝药物的患者在抗凝治疗后均于ASL像上表现为高灌注。本组16例中,24例于SWI像上显示梗死区或周围血管增多、增粗,占52%。SWI像上9例可见沿大脑中动脉走行的条状低信号影,占20%。NIHSS评分:1例死亡,5例无变化,其余40例经治疗后均有不同程度好转。结论 联合运用3D-ASL和SWI技术指导急性大面积脑梗死患者的治疗,具有重要的临床价值。 展开更多
关键词 3D-ASL SWI 急性大面积脑梗死 溶栓治疗
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红芪多糖3的荧光标记及其组织分布研究 被引量:5
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作者 师志强 张雪梅 +4 位作者 薛志远 陈宇 杨亚飞 封士兰 赵良功 《西北药学杂志》 CAS 2018年第5期611-615,共5页
目的对红芪多糖3(HPS-3)进行荧光标记,并研究其在小鼠组织中的分布特征。方法以异硫氰酸酯FITC为探针,对HPS-3进行标记;采用荧光分光光度法测定荧光标记的红芪多糖(HPS-3-FITC)在小鼠各组织中的质量浓度,并以FITC为阴性对照,探讨HPS-3-F... 目的对红芪多糖3(HPS-3)进行荧光标记,并研究其在小鼠组织中的分布特征。方法以异硫氰酸酯FITC为探针,对HPS-3进行标记;采用荧光分光光度法测定荧光标记的红芪多糖(HPS-3-FITC)在小鼠各组织中的质量浓度,并以FITC为阴性对照,探讨HPS-3-FITC在小鼠体内的组织分布特征。结果实现FITC对HPS-3的荧光标记,其取代度为1.71%;小鼠心、肝、脾、肺、肾、胃、肠和脑的药时曲线下面积(AUC)分别为31.51,291.81,23.67,103.65,326.14,21.89,23.53和0.36μg·mL^(-1)·h。结论成功实现了HPS-3的荧光标记,绝大多数药物聚集在肾和肝,有明显肾肝靶向性。 展开更多
关键词 红芪多糖3 异硫氰酸酯(FITC) 荧光标记 组织分布
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关于图的L(3,2 ,1)-标号问题(英文) 被引量:5
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作者 邵振东 刘家壮 《应用数学》 CSCD 北大核心 2004年第4期596-602,共7页
图G的L( 2 ,1 )标号是一个从顶点集V(G)到非负整数集的函数f(x) .使得若d(x ,y) =1 .则|f(x) -f(y) |≥ 2 ;若d(x ,y) =2 ,则|f(x) -f(y)|≥ 1 .图G的L( 2 ,1 )标号数λ(G)是使得G有max{f(v) ∶v∈V(G) }=k的L( 2 ,1 )标号中的最小... 图G的L( 2 ,1 )标号是一个从顶点集V(G)到非负整数集的函数f(x) .使得若d(x ,y) =1 .则|f(x) -f(y) |≥ 2 ;若d(x ,y) =2 ,则|f(x) -f(y)|≥ 1 .图G的L( 2 ,1 )标号数λ(G)是使得G有max{f(v) ∶v∈V(G) }=k的L( 2 ,1 )标号中的最小数k .本文将L( 2 ,1 ) 标号问题推广到更一般的情形即L( 3,2 ,1 ) 标号问题 .我们首先定义了图G的顶点 3 着色及图的 3 色数 χ3 (G)等有关概念 ,并推导出 3 色数 χ3 (G)的上界 ;然后根据 χ3 (G)与λ3 (G)的关系 ,得出了对一般图G ,有λ3 (G) ≤ 3maxH Gδ(H) (Δ2 -Δ+ 1 )这一一般关系式 ;最后证明了对一般平面图G ,有λ3 (G)≤ 1 5(Δ2 -Δ+ 1 ) ,并得出了其它几类平面图的λ3 (G)的上界 . 展开更多
关键词 L(3 2 1)—标号 顶点2—着色 2—色数
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3-正丁基锡-N-琥珀酰亚胺苯甲酸酯的合成及其^(125)I标记 被引量:4
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作者 刘振锋 汪勇先 +3 位作者 周伟 王丽华 夏姣云 尹端沚 《同位素》 CAS 北大核心 2005年第3期148-152,共5页
合成了3-正丁基锡-N-琥珀酰亚胺苯甲酸酯(ATE)和N-琥珀酰亚胺-3-碘苯甲酸酯(SIB),其产率分别为45.4%和71.4%,并用核磁、质谱、红外等对它们的结构进行了表征。对ATE进行了125I标记,得到S125IB,标记率可达93.0%,放化纯度>98.0%。本方... 合成了3-正丁基锡-N-琥珀酰亚胺苯甲酸酯(ATE)和N-琥珀酰亚胺-3-碘苯甲酸酯(SIB),其产率分别为45.4%和71.4%,并用核磁、质谱、红外等对它们的结构进行了表征。对ATE进行了125I标记,得到S125IB,标记率可达93.0%,放化纯度>98.0%。本方法为放射性药物碘的间接标记提供了重要参考。 展开更多
关键词 3-正丁基锡-N-琥珀酰亚胺苯甲酸酯(ATE) N-琥珀酰亚胺-3-碘苯甲酸酯(SIB) ^125I标记
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联合应用SWI与3D ASL成像对轻型颅脑损伤的应用价值 被引量:8
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作者 谢秀海 赵振国 +3 位作者 钱帮伟 隋海晶 杨柳青 杨文进 《中国医学计算机成像杂志》 CSCD 北大核心 2019年第3期227-230,共4页
目的:联合应用磁敏感加权成像(SWI)与三维动脉自旋标记成像(3D ASL)技术,探讨其对轻型颅脑损伤(mTBl)患者的临床应用价值。方法:收集45例符合急性轻型颅脑损伤的患者与25例正常体检者纳入本项研究,两组均行常规MRI及SWI与3DASL检査,并... 目的:联合应用磁敏感加权成像(SWI)与三维动脉自旋标记成像(3D ASL)技术,探讨其对轻型颅脑损伤(mTBl)患者的临床应用价值。方法:收集45例符合急性轻型颅脑损伤的患者与25例正常体检者纳入本项研究,两组均行常规MRI及SWI与3DASL检査,并在检査3个月后进行脑震荡综合征问卷(RPQ)评分,观察影像表现及其与脑震荡综合征(PCS)发生率的关系。结果:本组患者PCS阳性15例,SWI检出微出血灶13例,其中8例⑹.53%)PCS阳性;出现局部脑血流灌注减低区21例,其中12例(57.14%)PCS阳性。存在脑微出血及(或)局部灌注异常组出现PCS阳性概率明显高于无明显异常组(P<0.01)。结论:联合SWI、3D ASL可检出轻型颅脑损伤患者出现的脑微出血及脑血流灌注异常,出现这些异常的患者较易迁延成脑震荡综合征,及时检出与处理对于改善患者预后具有重要意义。 展开更多
关键词 轻型颅脑损伤 磁敏感加权成像 三维动脉自旋标记 脑震荡综合征
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NHS-MAG_3为螯合剂的^(99m)Tc-寡核苷酸标记特性 被引量:1
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作者 张春 谭天秩 +3 位作者 匡安仁 李云春 郑建国 潘卫民 《四川大学学报(医学版)》 CAS CSCD 北大核心 2004年第2期169-171,共3页
目的 探讨以 NHS- MAG3作为螯合剂的 99m Tc-寡核苷酸 (99m Tc- ON)的标记特性。方法 将 NHS-MAG3与长度为 15个碱基的 c- m yc m RNA的反义 (ASON)、正义 (SON)和无义寡核苷酸 (MON)偶联 ,进行 99m Tc标记 ,Sephadex G2 5柱层析分离... 目的 探讨以 NHS- MAG3作为螯合剂的 99m Tc-寡核苷酸 (99m Tc- ON)的标记特性。方法 将 NHS-MAG3与长度为 15个碱基的 c- m yc m RNA的反义 (ASON)、正义 (SON)和无义寡核苷酸 (MON)偶联 ,进行 99m Tc标记 ,Sephadex G2 5柱层析分离纯化 ,评价 99m Tc- ON的标记率、放化纯和稳定性 ;将 ON- MAG3偶联物置 - 2 0℃贮存 15 d、1月、2月后进行 99m Tc标记 ,观察标记率的变化 ,评价 ON- MAG3的稳定性 ;用三氯乙酸沉淀法测定 99m Tc-ON的血浆蛋白结合率。结果  99m Tc- ASON、99m Tc- SON和 99m Tc- MON的标记率分别为 6 8.4 1%、6 6 .2 4 %和6 9.38% ,纯化后放化纯分别为 96 .98%、95 .34%和 94 .6 2 %。三者在室温和血清中均较稳定。 ON- MAG3在 - 2 0℃保存 2月后 ,标记率未见明显下降。三种 99m Tc- ON的血浆蛋白结合率均小于 13%。结论 以 NHS- MAG3作为螯合剂的 99m Tc- ON具备优良的标记特性 ,标记率、放化纯较高 ,稳定性好 ,血浆蛋白结合率低 。 展开更多
关键词 NHS-MAG3 C-MYC 寡核苷酸 反义 ^99MTC标记
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