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1.
Hans‐Peter Brack Denise Ruegg Heinrich Bührer Michal Slaski Selmiye Alkan Günther G. Scherer 《Journal of Polymer Science.Polymer Physics》2004,42(13):2612-2624
The influence of irradiation and grafting on the crystallinity of three base polymers has been investigated with differential scanning calorimetry. Grafting has the largest effect on the base polymer crystallinity and results in a reduction of the crystallinity. The thermal degradation of the base polymers and grafted films has been investigated with thermogravimetric analysis. The extent of the fluorination of the base polymer, the irradiation method, and the graft level all influence the thermal degradation and its activation energy. It is proposed that the variation of the chain lengths of the grafted polystyrene chains is actually a primary underlying factor responsible for the influence of these various parameters on the degradation process. The first results of a comparative thermal analysis of some fuel‐cell membranes are also presented, and the promise and shortcomings of this method are discussed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2612–2624, 2004 相似文献
2.
CM Silva MF Duarte ML Mira MH Florêncio K Versluis AJ Heck 《Rapid communications in mass spectrometry : RCM》1999,13(12):1098-1103
Fast atom bombardment, combined with high-energy collision-induced tandem mass spectrometry, has been used to investigate gas-phase metal-ion interactions with captopril, enalaprilat and lisinopril, all angiotensin-converting enzyme inhibitors.Suggestions for the location of metal-binding sites are presented. For captopril, metal binding occurs most likely at both the sulphur and the nitrogen atom. For enalaprilat and lisinopril, binding preferably occurs at the amine nitrogen. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
3.
P. Goddard W. Nahm D. I. Olive H. Ruegg A. Schwimmer 《Communications in Mathematical Physics》1987,112(3):385-408
We analyse further the algebraic structure of dependent fermions, namely ones interrelated by the vertex operator construction. They are associated with special sorts of lattice systems which are introduced and discussed. The explicit evaluation of the relevant cocycles leads to the result that the operator product expansion of the fermions is related in a precise way to one or another of the division algebras given by complex numbers, quaternions or octonions. The latter case is seen to be realised in the light cone formalism of superstring theory. 相似文献
4.
The generalization of the isoparity (G-parity) for an arbitrary internal symmetry group is the problem of adjoining appropriately the charge conjugation operation, thereby extending the group. A complete solution to this problem is given, and explicitly detailed for the four families of compact, simple and simply-connected Lie groups (
andSp
n
).The extended isoparity is shown to depend upon the structure of the groups in question, and the required structure is developed and summarized. The properties of the extended isoparity are discussed and two special cases — strongG-parity and weakG-parity — are treated in more detail.National Science Foundation Senior Postdoctoral Fellow on leave from Duke University, Durham, North Carolina, U. S. A.N.A.T.O. Postdoctoral Fellow. A part of this work was done at the Institute for Advanced Study (Princeton) supported by a grant of the Air Force Office of Scientific Research, Office of Aerospace Research, United States Air Force, under AFOSR Nr 42.65 相似文献
5.
It is shown that the usual axioms of one-particle Quantum Mechanics can be implemented with projection operators belonging to the exceptional Jordan algebraJ
8
3
over real octonions. Certain lemmas on these projection operators are proved by elementary means. Use is made of the Moufang projective plane. It is shown that this plane can be orthocomplemented and that there exists a unique probability function. The result of successive, compatible experiments is shown not to depend on the order in which they are performed, in spite of the non-associativity of octonion multiplication. The algebra of observables and the action of the exceptional groupF
4 is studied, as well as a possible relation with the color group SU(3) and quark confinement.Work supported by the Swiss National Science Foundation 相似文献
6.
Catarina IV Ramos Flávio Figueira Marcelo D Polêto Francisco ML Amado Hugo Verli João PC Tomé M Graça PMS Neves 《Journal of mass spectrometry : JMS》2016,51(5):342-349
Electrospray mass spectrometry/mass spectrometry was used to investigate the gas‐phase properties of protonated expanded porphyrins, in order to correlate those with their structure and conformation. We have selected five expanded meso‐pentafluorophenyl porphyrins, respectively, a pair of oxidized/reduced fused pentaphyrins (22 and 24 π electrons), a pair of oxidized/reduced regular hexaphyrins (26 and 28 π electrons) and a regular doubly N‐fused hexaphyrin (28 π electrons). The gas‐phase behavior of the protonated species of oxidized and reduced expanded porphyrins is different. The oxidized species (aromatic Hückel systems) fragment more extensively, mainly by the loss of two HF molecules. The reduced species (Möbius aromatic or Möbius‐like aromatic systems) fragment less than their oxidized counterparts because of their increased flexibility. The protonated regular doubly fused hexaphyrin (non‐aromatic Hückel system) shows the least fragmentation even at higher collision energies. In general, cyclization through losses of HF molecules decreases from the aromatic Hückel systems to Möbius aromatic or Möbius‐like aromatic systems to non‐aromatic Hückel systems and is related to an increase in conformational distortion. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
7.
8.
Reynolds BJ Ruegg ML Mates TE Radke CJ Balsara NP 《Langmuir : the ACS journal of surfaces and colloids》2006,22(22):9192-9200
Dynamics of adsorption and desorption of a diblock copolymer to an interface between two homopolymers was measured using dynamic secondary-ion mass spectrometry (SIMS). Thin films were constructed consisting of a layer of saturated polybutadiene with 90% 1,2-addition (sPB90), followed by a layer of saturated polybutadiene with 63% 1,2-addition (sPB63), and finally by another layer of the sPB90 homopolymer. A sPB90-sPB63 diblock copolymer was initially included only in the top sPB90 layer of the film at a volume fraction of 0.05. The thin films were annealed at ambient temperature for times ranging between 0.2 and 108 h, and the concentration profiles of the diblock copolymer through the films were measured using SIMS. The dynamics of adsorption and desorption of the diblock copolymer at the two sPB90-sPB63 interfaces was gauged by comparing the different transient concentration profiles. The sorption process was modeled as diffusion in an external field, generated from self-consistent field theory (SCFT). All parameters for the model were determined independently. Although the model neglects the dynamics of conformational change, experimental results matched theory very well. 相似文献
9.
Aaron G Filler Garth T Whiteside Mark Bacon Martyn Frederickson Franklyn A Howe Miri D Rabinowitz Alan J Sokoloff Terrence W Deacon Chris Abell Raj Munglani John R Griffiths B Anthony Bell Andrew ML Lever 《BMC neuroscience》2010,11(1):1-26
Background
Targeted delivery of pharmaceutical agents into selected populations of CNS (Central Nervous System) neurons is an extremely compelling goal. Currently, systemic methods are generally used for delivery of pain medications, anti-virals for treatment of dermatomal infections, anti-spasmodics, and neuroprotectants. Systemic side effects or undesirable effects on parts of the CNS that are not involved in the pathology limit efficacy and limit clinical utility for many classes of pharmaceuticals. Axonal transport from the periphery offers a possible selective route, but there has been little progress towards design of agents that can accomplish targeted delivery via this intraneural route. To achieve this goal, we developed a tripartite molecular construction concept involving an axonal transport facilitator molecule, a polymer linker, and a large number of drug molecules conjugated to the linker, then sought to evaluate its neurobiology and pharmacological behavior.Results
We developed chemical synthesis methodologies for assembling these tripartite complexes using a variety of axonal transport facilitators including nerve growth factor, wheat germ agglutinin, and synthetic facilitators derived from phage display work. Loading of up to 100 drug molecules per complex was achieved. Conjugation methods were used that allowed the drugs to be released in active form inside the cell body after transport. Intramuscular and intradermal injection proved effective for introducing pharmacologically effective doses into selected populations of CNS neurons. Pharmacological efficacy with gabapentin in a paw withdrawal latency model revealed a ten fold increase in half life and a 300 fold decrease in necessary dose relative to systemic administration for gabapentin when the drug was delivered by axonal transport using the tripartite vehicle.Conclusion
Specific targeting of selected subpopulations of CNS neurons for drug delivery by axonal transport holds great promise. The data shown here provide a basic framework for the intraneural pharmacology of this tripartite complex. The pharmacologically efficacious drug delivery demonstrated here verify the fundamental feasibility of using axonal transport for targeted drug delivery. 相似文献10.