排序方式: 共有34条查询结果,搜索用时 15 毫秒
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Kunio Iwatsuki 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2006,82(8):270-277
A new term, spherophylon, indicates a unit of life higher than the individual level. To define this term, critical notes are given on the meaning of age in terms of life, the interrelationships among the elements of biodiversity, and an analogy of development between the multicellular body of an individual and the spherophylon. Life is compared at various levels; at the level of the cell, the individual as a multicellular organism, and the spherophylon. The biology of the spherophylon is discussed in the context of integrative biology. 相似文献
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Dr. Denis A. Malyshev Prof. Floyd E. Romesberg 《Angewandte Chemie (International ed. in English)》2015,54(41):11930-11944
All biological information, since the last common ancestor of all life on Earth, has been encoded by a genetic alphabet consisting of only four nucleotides that form two base pairs. Long‐standing efforts to develop two synthetic nucleotides that form a third, unnatural base pair (UBP) have recently yielded three promising candidates, one based on alternative hydrogen bonding, and two based on hydrophobic and packing forces. All three of these UBPs are replicated and transcribed with remarkable efficiency and fidelity, and the latter two thus demonstrate that hydrogen bonding is not unique in its ability to underlie the storage and retrieval of genetic information. This Review highlights these recent developments as well as the applications enabled by the UBPs, including the expansion of the evolution process to include new functionality and the creation of semi‐synthetic life that stores increased information. 相似文献
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从在中山医科大学附属三院妇科门诊临床初诊为尿道炎的妇性患者的尿道分泌物中,分别两次,间隔4d,重复分离出相同的ALO菌株。 相似文献
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J. Yoshinaga Y. Shibata T. Horiguchi M. Morita 《Accreditation and quality assurance》1997,2(3):154-156
The National Institute for Environmental Studies (NIES) recently prepared two candidate certified reference materials (CRMs)
for arsenicals to meet the growing demand for the quality assurance of arsenic speciation analysis. The NIES candidate CRM
No. 14 Brown Alga was prepared from Hijiki seaweed for the certification of inorganic arsenic content, and No. 15 Scallop was prepared from adductor muscle of scallop
for the certification of arsenobetaine content. The preparation of the candidate CRMs is briefly described. Cooperative analyses
for total arsenic content of the candidate CRMs have been underway. The preliminary speciation analysis at NIES revealed difficulty
in establishing suitable conditions for extracting arsenic species from the materials. Chromatograms of arsenic species by
a high performance liquid chromatography-inductively coupled plasma mass spectrometric detection system are presented to provide
information about arsenic species present in these candidate CRMs. 相似文献
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Rapid amplification of genetically modified organisms using a circular ferrofluid-driven PCR microchip 总被引:1,自引:0,他引:1
Yi Sun Yien-Chian Kwok Peter Foo-Peng Lee Nam-Trung Nguyen 《Analytical and bioanalytical chemistry》2009,394(5):1505-1508
The use of genetically modified organisms (GMOs) as food and in food products is becoming more and more widespread. Polymerase
chain reaction (PCR) technology is extensively used for the detection of GMOs in food products in order to verify compliance
with labeling requirements. In this paper, we present a novel close-loop ferrofluid-driven PCR microchip for rapid amplification
of GMOs. The microchip was fabricated in polymethyl methacrylate by CO2 laser ablation and was integrated with three temperature zones. PCR solution was contained in a circular closed microchannel
and was driven by magnetic force generated by an external magnet through a small oil-based ferrofluid plug. Successful amplification
of genetically modified soya and maize were achieved in less than 13 min. This PCR microchip combines advantages of cycling
flexibility and quick temperature transitions associated with two existing microchip PCR techniques, and it provides a cost
saving and less time-consuming way to conduct preliminary screening of GMOs.
Figure Schematic of the circular ferrofluid-driven PCR microchip 相似文献
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高效毛细管电泳分析羊栖菜多糖对肿瘤机体红细胞合淌度的影响 总被引:3,自引:0,他引:3
为了分析羊栖菜多糖(SFPS)对肿瘤机体红细胞合淌度的影响,建立了肿瘤动物模型,分高、中、低剂量腹腔给予羊栖菜多糖7 d,采集并制备红细胞悬液,应用高效毛细管电泳法检测红细胞的合淌度。实验条件:毛细管为75 μm×50 cm,电泳缓冲液为含2 g/L羟丙基甲基纤维素的磷酸盐溶液(0.1 mol/L,pH 7.4),压力进样为3.448 kPa×10 s,分离电压为20 kV,柱温为25 ℃,电渗淌度为2.16×10-4 cm2·V-1·s-1。实验结果表明:羊栖菜多糖能降低肿瘤机体红细胞的电泳迁移时间(阴性对照组为15.76 min,SFPS低剂量组为13.96 min,SFPS中剂量组为12.90 min,SFPS高剂量组为13.51 min,正常对照组为11.51 min),增加红细胞的合淌度(阴性对照组为1.06×10-4 cm2·V-1·s-1,SFPS低剂量组为1.19×10-4 cm2·V-1·s-1,SFPS中剂量组为1.29×10-4 cm2·V-1·s-1,SFPS高剂量组为1.23×10-4 cm2·V-1·s-1,正常对照组为1.45×10-4 cm2·V-1·s-1),SFPS 3个剂量组红细胞的合淌度与阴性对照组比较均有非常显著的差异(P<0.01)。羊栖菜多糖能够改变肿瘤机体红细胞的合淌度,并使之趋向于正常机体水平,这可能与其改变红细胞表面的电荷密度有关。高效毛细管电泳法可以作为检测红细胞生理状态和功能的一种辅助工具。 相似文献
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Katherine E. Zink Denise A. Tarnowski Mark J. Mandel Laura M. Sanchez 《Journal of mass spectrometry : JMS》2020,55(4)
Tissue sections have long been the subject matter for the application of imaging mass spectrometry, but recently the technique has been adapted for many other purposes including bacterial colonies and 3D cell culture. Here, we present a simple preparation method for unsectioned invertebrate tissue without the need for fixing, embedding, or slicing. The protocol was used to successfully prepare a Hawaiian bobtail squid hatchling for analysis, and the resulting data detected ions that correspond to compounds present in the host only during its symbiotic colonization by Vibrio fischeri. 相似文献