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排序方式: 共有198条查询结果,搜索用时 15 毫秒
191.
Dr. Haitao Yu Dr. Angelina Angelova Dr. Borislav Angelov Dr. Brendan Dyett Dr. Lauren Matthews Yiran Zhang Mohamad El Mohamad Xudong Cai Dr. Sepideh Valimehr Prof. Calum J. Drummond Dr. Jiali Zhai 《Angewandte Chemie (International ed. in English)》2023,62(35):e202304977
Ionisable amino-lipid is a key component in lipid nanoparticles (LNPs), which plays a crucial role in the encapsulation of RNA molecules, allowing efficient cellular uptake and then releasing RNA from acidic endosomes. Herein, we present direct evidence for the remarkable structural transitions, with decreasing membrane curvature, including from inverse micellar, to inverse hexagonal, to two distinct inverse bicontinuous cubic, and finally to a lamellar phase for the two mainstream COVID-19 vaccine ionisable ALC-0315 and SM-102 lipids, occurring upon gradual acidification as encountered in endosomes. The millisecond kinetic growth of the inverse cubic and hexagonal structures and the evolution of the ordered structural formation upon ionisable lipid-RNA/DNA complexation are quantitatively revealed by in situ synchrotron radiation time-resolved small angle X-ray scattering coupled with rapid flow mixing. We found that the final self-assembled structural identity, and the formation kinetics, were controlled by the ionisable lipid molecular structure, acidic bulk environment, lipid compositions, and nucleic acid molecular structure/size. The implicated link between the inverse membrane curvature of LNP and LNP endosomal escape helps future optimisation of ionisable lipids and LNP engineering for RNA and gene delivery. 相似文献
192.
Angelina Y. M. Chin 《Proceedings Mathematical Sciences》2009,119(2):145-148
Let R be a ring with identity. An element in R is said to be clean if it is the sum of a unit and an idempotent. R is said to be clean if all of its elements are clean. If every idempotent in R is central, then R is said to be abelian. In this paper we obtain some conditions equivalent to being clean in an abelian ring. 相似文献
193.
Angelina N. Kravchenko Pavel A. Poluboyarov Sergei V. Vasilevskii Galina A. Gazieva Yulia V. Nelyubina 《Mendeleev Communications》2012,22(2):90-91
[3 + 2]-Cycloaddition of azomethine ylide generated from formaldehyde and sarcosine at the double bond of 1,3-dimethyl-6-(2-oxo-1,2-dihydro-3H-indol-3-ylidene)-3a,9a-diphenyl-3,3a,9,9a-tetrahydroimidazo[4,5e][1,3]thiazolo[3,2-b][1,2,4]triazine-2,7(1H,6H)-diones occurs stereospecifically at the face opposite to the phenyl substituents. Product 3a crystallizes as a conglomerate. 相似文献
194.
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196.
Angelina Altomare Luisa Andruzzi Francesco Ciardelli Michele Mader Nicola Tirelli Roberto Solaro 《Macromolecular Symposia》1999,137(1):33-46
Three photochromic monomers containing a permanent dipole photochromic azobenzene group spaced from the methacryloyl moiety by a polymethylene segment were synthesized in three steps starting from 4-cyanoaniline. The monomers were homopolymerized and copolymerized with an optically active monomer, (-)-menthyl methacrylate, in the presence of AIBN as a radical initiator. Structurally similar amphiphilic polymers were obtained by homopolymerization of analogous methacrylates in which oligo(oxyethylene) segments replaced the polymethylene spacers. The polymeric materials, having a molar content of photochromic units between 5 and 100% and molecular weights of about 15,000, were characterized by thermal analysis, X-ray diffraction, 1D and 2D NMR. Mobility and photochromic properties in solution were also investigated. 相似文献
197.
Angelina Altomare Roberto Solaro Francesco Ciardelli Lia Barazzoni Francesco Menconi Francesco Masi 《Macromolecular Symposia》1992,59(1):369-379
Homopolymerization of 4-methyl-1-pentene carried out in the presence of catalysts containing variable relative amounts of Ti, Hf and Mg indicates that molecular weight and stereoregularity can be varied to an appreciable extent depending on catalyst nature and composition. A distinct behaviour of the various catalytic systems is also observed during the copolymerization of 4-methyl-1-pentene with monoalkenes such as propylene, 1-butene and 1-hexene. These data are discussed by underlining the important role of the transition metal in determining the features of polyolefins materials. 相似文献
198.
Francesco Ciardelli Angelina Altomare Giuseppe Conti Guillermo Arribas Bernardo Mendez Alida Ismayel 《Macromolecular Symposia》1994,80(1):29-44
Macromolecular ligands have been widely used in the past two decades with the objective of preparing structurally defined heterogeneous catalysts from soluble organometallic complexes. This activity has been largely reconsidered and focused on few specific systems. In this connection the present paper reviews recent data concerning the preparation of macromolecular metal complexes derived from transition metals which can produce active catalytic complexes for olefin polymerization and oligomerization and comparison is made about the suitability of both organic resins (crosslinked polystyrene) and inorganic materials (silica, alumina and zeolites). 相似文献