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101.
Abstract Tetraphenylporphinesulfonate (TPPS4) is a synthetic porphyrin that localizes in certain tumors to a higher absolute concentration and with more favorable tumor to other tissue ratios than any other porphyrin yet studied. Its utilization for photodynamic therapy and other applications has been inhibited by reported neurotoxicity. We injected TPPS4 over a broad dose range of 5-150 mg kg?1 and observed the effects on peripheral nerve in groups of animals sacrificed 35, 70 and 140 days later. No immediate deaths or phototoxic manifestations were seen. Light and electron microscopy, however, revealed cytoskeletal abnormalities and nerve fiber degeneration affecting both myelinated and unmyelinated fibers in all the time and dose groups. These findings have similarities to those of other experimental toxic neuropathies, and may also be related to the preponderance of autonomic manifestations in patients with porphyric neuropathy. The morphological changes consisted of tangles of fibrillar material in the myelinated fibers and loss of neurotubules in the unmyelinated fibers. Our studies indicate a direct interaction of TPPS4 with tubulin. This biological mechanism may be involved in the selective distribution of certain parenterally administered porphyrins. 相似文献
102.
A. M. Kolchinskaya V. E. Dmitrienko S. Collins E. N. Ovchinnikova A. P. Oreshko 《Crystallography Reports》2009,54(4):719-720
Crystallography Reports - 相似文献
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We show that the wide distribution of time constants required to explain 1/ƒ noise in MOSFETs arises as a natural consequence of the multi-phonon model of carrier trapping into individual Si-SiO2 interface states. A new class of random telegraph signal found in the drain current of small-area silicon MOSFETs is described. These signals are a result of defect metastability and are shown to be a source of non-Gaussian noise. 相似文献
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109.
The site occupation of indium solutes in Ni2Al3-type compounds was determined using perturbed angular correlation of gamma rays. Measurements were made for compositions
on both sides of the stoichiometric composition. Sites were identified through their quadrupole interactions. For transition-metal
(TM) rich aluminides and galliumides, indium solutes occupy only one of two inequivalent trivalent-metal sites (Al or Ga).
For TM-poor aluminides, indium solutes tend to locate at noncrystallographic sites such as in grain boundaries. For TM-poor
galliumides, the solutes occupy nickel sites while close to the stoichiometric composition they also occupy sites on an empty
Ni-sublattice. Composition dependences of site preference for indium solutes in Pt2Al3 and Ni2Ga3 are examined in terms of a recently developed thermodynamic model.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
110.
Xinnan Zhang Gang‐Chi Chen Andrew Collins Solomon Jacobson Paul Morganelli Yadunandan L. Dar Osama M. Musa 《Journal of polymer science. Part A, Polymer chemistry》2009,47(4):1073-1084
New thermosetting materials were developed for reworkable adhesive applications by introducing acetal ester groups as thermally degradable linkages into maleimide compounds. The synthesis of compounds containing maleimide functionality and acetal ester linkages was conducted by a one‐step neat reaction from commercially available materials. The polymerization process and thermal degradation of the synthesized materials were studied. It was found that the acetal ester linkage degraded rapidly above 225 °C, and introduction of this linkage into the adhesive formulation led to improved reworkability of adhesively bonded substrates. A mechanism for reworkability was proposed based on the insight provided by experimental and modeling work. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1073–1084, 2009 相似文献