排序方式: 共有47条查询结果,搜索用时 15 毫秒
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Lawrence CR Tafoya C William Shuttleworth Yuchio Yanagawa Kunihiko Obata Michael C Wilson 《BMC neuroscience》2008,9(1):105
Background
The soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex, comprised of SNAP-25, syntaxin 1A, and VAMP-2, has been shown to be responsible for action potential (AP)-dependent, calcium-triggered release of several neurotransmitters. However, this basic fusogenic protein complex may be further specialized to suit the requirements for different neurotransmitter systems, as exemplified by neurons and neuroendocrine cells. In this study, we investigate the effects of SNAP-25 ablation on spontaneous neuronal activity and the expression of functionally distinct isoforms of this t-SNARE in GABAergic and glutamatergic neurons of the adult brain. 相似文献42.
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Merritt ME Harrison C Mander W Malloy CR Sherry AD 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2007,189(2):280-285
The asymmetry in the doublet of a spin coupled to hyperpolarized (13)C has been used previously to measure the initial polarization of (13)C. We tested the hypothesis that a single observation of the (1)H NMR spectrum of hyperpolarized (13)C formate monitors (13)C polarization. Depending on the microwave frequency during the polarization process, in-phase or out-of-phase doublets were observed in the (1)H NMR spectrum. Even in this simple two-spin system, (13)C polarization was not reflected in the relative area of the J(CH) doublet components due to strong heteronuclear cross-relaxation. The Solomon equations were used to model the proton signal as a function of time after polarization and to estimate (13)C polarization from the (1)H NMR spectra. 相似文献
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Measuring the Physiologic Properties of Oral Lesions Receiving Fractionated Photodynamic Therapy 下载免费PDF全文
Shannon M. Gallagher‐Colombo Harry Quon Kelly M. Malloy Peter H. Ahn Keith A. Cengel Charles B. Simone II Ara A. Chalian Bert W. O'Malley Gregory S. Weinstein Timothy C. Zhu Mary E. Putt Theresa M. Busch 《Photochemistry and photobiology》2015,91(5):1210-1218
Photodynamic therapy (PDT) can treat superficial, early‐stage disease with minimal damage to underlying tissues and without cumulative dose‐limiting toxicity. Treatment efficacy is affected by disease physiologic properties, but these properties are not routinely measured. We assessed diffuse reflectance spectroscopy (DRS) for the noninvasive, contact measurement of tissue hemoglobin oxygen saturation (StO2) and total hemoglobin concentration ([tHb]) in the premalignant or superficial microinvasive oral lesions of patients treated with 5‐aminolevulinic acid (ALA)‐PDT. Patients were enrolled on a Phase 1 study of ALA‐PDT that evaluated fluences of 50, 100, 150 or 200 J cm?2 delivered at 100 mW cm?2. To test the feasibility of incorporating DRS measurements within the illumination period, studies were performed in patients who received fractionated (two‐part) illumination that included a dark interval of 90–180 s. Using DRS, tissue oxygenation at different depths within the lesion could also be assessed. DRS could be performed concurrently with contact measurements of photosensitizer levels by fluorescence spectroscopy, but a separate noncontact fluorescence spectroscopy system provided continuous assessment of photobleaching during illumination to greater tissue depths. Results establish that the integration of DRS into PDT of early‐stage oral disease is feasible, and motivates further studies to evaluate its predictive and dosimetric value. 相似文献
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The CF(3) signals in the (13)C{(1)H} spectrum of 1,1,1,3,3,3-hexafluoroisopropyl alcohol and the (CF(3))(2) CH signals in the corresponding triflate exhibit much greater complexity than might first be expected. The same holds for the (13)C satellites in the (19)F spectra. Complex patterns appear because of higher order effects resulting from the combination of a relatively large four-bond (19)F-(19)F J coupling in the ((13)CF(3))(12)CH((12)CF(3))-containing isotopomer and a typical large one-bond (13)C/(12)C isotope effect on the (19)F chemical shift. This complexity cannot be eliminated at very high magnetic field strengths. The triflate (CF(3))(2)CH-O-SO(2)CF(3) presents still additional complexity because of the presence of two different types of CF(3) groups exhibiting (6)J(FF) in any of the isotopomers and the chemical shift differences in hertz between the various (19)F signals in the two different (13)CF(3)-containing isotopomers. In addition, the presence of a small (5)J(CF) in the ((13)CF(3))((12)CF(3))(12)CH-O-SO(2) (12)CF(3) isotopomer is revealed only through simulations. The hexafluoroisopropyl CF(3) groups in the alcohol and triflate and the SO(2)CF(3) group in the triflate apparently provide the first examples of cross-correlated relaxation in (13)CF(3) groups. An analysis of the spectra in the context of previously reported work highlights the novel aspects of our findings. In particular, for each part of the complex hexafluoroisopropyl CF(3) quartet, peak height and linewidth variations resulting from cross-correlated relaxation are observed. These variations within a group of (13)C signals reflect different spin-lattice and spin-spin relaxation rates for the transitions within that group arising from higher order coupling effects. 相似文献
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Maria Ashioti John S Beech Andrew S Lowe Michel Bernanos Andrew McCreary Michel M Modo Steve CR Williams 《BMC neuroscience》2009,10(1):82