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51.
Yu P Strug I Cafarella TR Seaton BA Krantz A 《Organic & biomolecular chemistry》2012,10(23):4500-4504
Annexin V (1) specifically binds to phosphatidylserine on apoptotic and necrotic cells as well as certain cancer cells, making it an attractive vehicle for the delivery of therapeutically-relevant conjugates to such sites. The wild-type protein possesses a single thiol at Cys316, which is difficultly accessible to site-specific labeling by simple maleimides. By contrast, 1,4-benzoquinone site-specifically labels annexin V in minutes. The resulting conjugate (5) serves as an intermediate for crosslinking annexin molecules, which can be accomplished within hours either directly for linking annexin V-128 (19), or via an extended sequence involving the crosslinking of two units of (5) by the symmetrical α,ω-dithiol (20). Besides its ability to mediate protein dimer formation while retaining annexin V's ability to bind phosphatidylserine, (5) possesses classic 1,4-benzoquinone reactivity. Various nucleophiles and Diels-Alder dienes form adducts with (5) in reactions that may have general utility for the synthesis of novel biologically active entities. The present work presents the first example of thiol-specific crosslinking of proteins by 1,4-quinone-based methodology designed to exploit the reactivity of this versatile chemical entity. 相似文献
52.
Composite membranes based on sulfonated silica/sulfonated poly(ether ether ketone)(SPEEK) were prepared by means of sol-gel method so as to gain a high conductivity and reasonable methanol permeability.The sulfonated silica is generated in situ via the hydrolysis of sulfonated 3-anminopropyl triethoxysilane(KH550) synthesized newly from 3-aminopropyl triethoxysilane and 1,4-butane sultone.The membrane with a silica mass fraction of 5% exhibits a conductivity of 0.187 S/cm at 80 °C and a methanol coefficient with 9.72×10-7 cm2/s.The composite membranes show improved condutive ability and better selectivity that can be promisingly used in direct methanol fuel cell. 相似文献
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IntroductionPoly( 3- alkylthiophenes) ( P3ATs) ,as a newkind of soluble,fusible and processable conductivepolymers,have attracted a great interest and muchattention ofchemistsand physicists[1,2 ] . Ithas beenwidely accepted that P3ATs can form similarlayered structures with alkyl side chains beingoriented in the lateral a- axis direction[3— 6] .Moreover,when the number of the carbon atoms inthe alkyl side chains is more than1 0 ,some orderlyarrangements of the side chains will occur between… 相似文献
56.
本文先通过缩合反应合成羟端基的二酰亚胺单体, 然后利用亲核缩聚反应, 与4,4′-二氯二苯砜及3,3′-二磺酸钠基-4,4′-二氯二苯砜共聚, 制备聚合物. 该合成路线反应周期短, 对温度和溶剂等条件要求不高, 简便易得. 相似文献
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以发烟硫酸和4,4′-二氯二苯砜为原料,通过磺化反应,制得磺化二氯二苯砜,然后利用亲核缩聚反应,调整磺化单体和非磺化单体的比例,与四甲基联苯二酚进行聚合,制取了系列具有不同磺化度的聚醚醚砜,并对聚合物的结构进行了研究. 相似文献
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L. Emily Cowie Hans-Christian Herbig Daniel Herden Christopher Seaton 《Journal of Pure and Applied Algebra》2019,223(1):395-421
Let V be a finite-dimensional representation of the complex circle determined by a weight vector . We study the Hilbert series of the graded algebra of polynomial -invariants in terms of the weight vector a of the -action. In particular, we give explicit formulas for as well as the first four coefficients of the Laurent expansion of at . The naive formulas for these coefficients have removable singularities when weights pairwise coincide. Identifying these cancelations, the Laurent coefficients are expressed using partial Schur polynomials that are independently symmetric in two sets of variables. We similarly give an explicit formula for the a-invariant of in the case that this algebra is Gorenstein. As an application, we give methods to identify weight vectors with Gorenstein and non-Gorenstein invariant algebras. 相似文献
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B. Betev J. J. Blaising P. Bordalo A. Boumediene L. Cerrito A. Degré A. Ereditato S. Falciano K. Freudenreich E. Gorini M. Guanziroli H. Hofer P. Juillot L. Kluberg P. Lecomte P. Le Coultre R. Morand B. Mours A. Romana R. Salmeron P. Strolin H. Suter V. L. Telegdi J. Varela G. Viertel J. Wallace-Hadrill M. Winter NA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1985,28(1):15-22