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911.
红细胞膜上各种磷脂中脂肪酸的测定   总被引:3,自引:0,他引:3  
张抒峰  常理文 《分析化学》1994,22(4):346-350
应用自制硅胶板的薄层色谱法分离了红细胞膜上四种主要磷脂。将分离后的每种磷脂斑点硅胶涂层刮下,不经萃取,直接在无水甲醇-苯-乙酰氯溶液中进行转移甲基化,然后用毛细管相色谱分离测定其脂肪酸组成和含量。上述方法已成功地用于先天愚型病人和正常人红细胞膜上各种磷脂中脂肪酸轮廓分析,获得有意义的结果。  相似文献   
912.
Since the feasibility of artificial cells was first demonstrated in 1957 [Chang (1, 2)], an increasing number of approaches to their preparation and use have become available. Thus artificial cell membranes can now be formed using a variety of synthetic or biological materials to produce desired variations in their permeability, surface properties, and blood compatibility. Almost any material can be included within artificial cells. These include enzyme systems, cell extracts, biological cells, magnetic materials, isotopes, antigens, antibodies, vaccines, hormones, adsorbents, and others. Since cells are the fundamental units of living organisms, it is not surprising that artificial cells can have a number of possible applications. This is especially so since artificial cells can be “tailor-made” to have very specialized functions. A number of potential applications suggested earlier have now reached a developmental stage appropriate for clinical trial or application. These clinical applications include the use of such cells as a red blood cell substitute, in hemoperfusion, in an artifical kidney or artificial liver, as detoxifiers, in an artificial pancreas, and so on. Artificial red blood cells based on lipid-coated fluorocarbon or crosslinked hemoglobin are being investigated in a number of centers. The principle of the artificial cells is also being used in biotechnology to immobilize enzymes and cells. Developments in biotechnology have also resulted in the use of the principle underlying the artificial cell to help produce interferons and monoclonal antibodies; to create immunosorbents; to develop an artificial pancreas; and to bring enzyme technology usefully into biotechnology and biomedical applications. Artificial cells are also being used as drug delivery systems based on slow release, on magnetic target delivery, on biodegradability, on liposomes, or other approaches. The present status and recent advances will be emphasized in this paper.  相似文献   
913.
The synthesis of '2('3)-O-(amino)acyl-pCpA derivatives is described and the products are characterized chemically and as substrates for T4 RNA ligase in the presence of E. coli tRNA phe-COH. The modified (N-acetylammo)acyl-tRNA's so derived are characterized by their chromatographic and biochemical properties, and by their ability to act as P-site tRNA donors in the peptidyltransferase reaction.  相似文献   
914.
制备了改性的x型和x/ZSM-5型沸石催化剂,并对其进行了评价和TPD、ESCA表征,将实验结果进行了关联。结果表明,采用KOH,H_3BO_3和碱土金属化合物等作为改性剂,可以调变沸石催化剂的酸碱中心,其中碱酸密度比为0.539的KX(B_3)·KZSM-5(Ca)催化剂,能显著提高甲苯、甲醇侧链烷基化制取苯乙烯反应的选择性和收率。井根据对实验结果的分析,初步探讨了甲苯、甲醇侧链烷基化反应的机理。  相似文献   
915.
甲苯甲醇侧链烷基化反应中沸石催化剂酸碱中心的作用Ⅰ.改性的X型、X/ZSM-5型和KX型沸石催化剂李永光,畅晋英,王建平(太原工业大学化工系,太原030024)关链词沸石,侧链烷基化,甲苯,甲醇甲苯甲醇烷基化反应有两种方式:在苯环上烷基化生成二甲苯;...  相似文献   
916.
A new bismaleimide (BMI) resin was synthesized to formulate epoxy(tetraglycidyl diaminodiphenyl methane; TGDDM) – bismaleimide thermoset blends for composite matrix applications. 4,4′-diaminodiphenyl methane (DDM) was used as an amine curing agent for the TGDDM. A Fourier transform infrared (FTIR) spectroscopy was employed to characterize the new BMI resin. Cure behavior of the epoxy–BMI blends was studied using a differential scanning calorimeter (DSC). DSC thermograms of the thermoset blends indicated two exothermic peaks. The glass transition temperature of the thermoset blends decreased with BMI content. Thermogravimetric analysis (TGA) was carried out to investigate thermal degradation behavior of the cured epoxy–BMI thermoset blends. The new BMI resin reacted partially with the DDM and weak intercrosslinking polymer networks were formed during cure of the thermoset blends.  相似文献   
917.
Two new compounds from Zingiber officinale   总被引:1,自引:0,他引:1  
A new cyclic diarylheptanoid,1,5-epoxy-3-hydroxy-1-(3-methoxy-4,5-dihydroxyphenyl)-7-(4-hydroxyphenyl)-heptane (1),as well as a new monoterpene,10-O-β-D-glucopyranosyl-hydroxy cineole (2) were isolated from the rhizomes of Zingiber officinale. The structures of compounds 1 and 2 were established based on their spectral data.In addition,the antioxidant activities of these compounds were also measured.  相似文献   
918.
Yoo HS  Kim JI  Yang N  Koh EK  Park JG  Hong CS 《Inorganic chemistry》2007,46(22):9054-9056
A new one-dimensional heterochiral coordination polymer [Co(bmdt)(N3)2].MeCN (1.MeCN) with well-isolated chains was prepared via a self-assembly process. Magnetic data show that intrachain ferromagnetic couplings via the single end-to-end azide group are observed, which is an extraordinary case among the azide-bridged Co(II) systems.  相似文献   
919.
Application of a novel sulfonate-based traceless multifunctional linker system using pentaerythritol as a tetrapodal soluble support was demonstrated using liquid-phase parallel and combinatorial preparation of biphenyl and terphenyl compounds. Nickel-catalyzed reactions of pentaerythritol tetrakis(arenesulfonate)s with arylmagnesium bromides generated the desired products in sufficient yields through reductive cleavage/cross-coupling of the C-S bond. Homogeneous pentaerythritol-supported reactions could be accomplished using less nucleophile with shorter reaction periods than could the corresponding heterogeneous polymer-supported reactions. This liquid-phase approach using a small polyfunctionalized support combines advantages of solution-phase and solid-phase syntheses by allowing high reactivity, high atom economy, simple isolation, and real-time monitoring of the reaction progress.  相似文献   
920.
Two new nickel(II) complexes, [Ni(4, 4′‐bpy)(H2O)4]n · n(cpp) · 0.5nH2O ( 1 ) and [Ni(cpp)(4, 4′‐bpy)(H2O)2]n ( 2 ) [4, 4′‐bpy = 4, 4′‐bipyridine, H2cpp = 3‐(4‐carboxyphenyl)propionic acid] were synthesized and characterized by single‐crystal X‐ray diffraction, elemental analysis, IR spectroscopy, and thermal analysis. In complex 1 , NiII ions are bridged by 4, 4′‐bpy into 1D chains, and cpp ligands are not involved in the coordination, whereas in complex 2 , cpp ligands adopt a bis(monodentate) mode and link NiII ions into 2D (4, 4) grids with the help of 4, 4′‐bpy ligands. Triple interpenetration occurs, which results in the formation of a complicated 3D network. The difference in the structures of the two complexes can be attributed to the different reaction temperatures and bases.  相似文献   
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