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41.
The purpose of this study was to observe and document variations in configuration and movement of the lower vocal tract and selected laryngeal structures in a sample of normal speakers. Ten men and ten women, ranging in age from 21 to 33 years, judged to have normal voices, were examined fiber-optically. Each subject engaged in a set protocol of phonatory and nonphonatory tasks and all examinations were videotaped. Judges reviewed these recordings with special attention to the following structures: pharyngeal wall, epiglottis, pyriform sinuses, ventricular folds, true vocal folds and the arytenoid complex. Extensive variability among these normals was observed anatomically and physiologically. 相似文献
42.
Dale R. Harshman Ralph Eric Turner Jess H. Brewer David P. Spencer 《Hyperfine Interactions》1986,32(1-4):527-533
Muonium (μ
+
e
−) in bulk fused quartz is a unique system in that theμ
+ spin polarization (in the muonium state) relaxes almost entirely via random anisotropic hyperfine distortions (RAHD). As
such, this system provides an excellent test case for a new RAHD spin relaxation theory. This theory is quantitatively compared
to static zero field data and the functional characteristics in both the high field and dynamic limits are considered as well. 相似文献
43.
K. Nishiyama K. Ishida K. Nagamine T. Matsuzaki Y. Kuno H. Shirakawa R. Kiefl J. H. Brewer 《Hyperfine Interactions》1986,32(1-4):551-556
The state of the muon in cis-polyacetylene was studied by muon spin rotation method under high transverse magnetic field.
The most of the muons are found to be in muonium substituted radical state. The hyperfine coupling constant was determined
to be 91 MHz with a line width of 10 MHz. 相似文献
44.
W. D. Brewer 《Hyperfine Interactions》1990,59(1-4):201-217
The rare-earth or lanthanoid series of elements offers a rich ground for the study of both solid-state phenomena and nuclear
physics. Some systematic investigations of these elements as host materials and as impurity isotopes have been performed using
the nuclear orientation methods, and more can be expected in the near future owing to recent technical developments. A review
of past work in this area is given, and the outlook for future experiments is summarized. 相似文献
45.
Ladie Kimberly De La Cruz Xiaoxiao Yang Anna Menshikh Maya Brewer Wen Lu Minjia Wang Siming Wang Xingyue Ji Alyssa Cachuela Haichun Yang David Gallo Chalet Tan Leo Otterbein Mark de Caestecker Binghe Wang 《Chemical science》2021,12(31):10649
Carbon monoxide as an endogenous signaling molecule exhibits pharmacological efficacy in various animal models of organ injury. To address the difficulty in using CO gas as a therapeutic agent for widespread applications, we are interested in developing CO prodrugs through bioreversible caging of CO in an organic compound. Specifically, we have explored the decarboxylation–decarbonylation chemistry of 1,2-dicarbonyl compounds. Examination and optimization of factors favorable for maximal CO release under physiological conditions led to organic CO prodrugs using non-calorific sweeteners as leaving groups attached to the 1,2-dicarbonyl core. Attaching a leaving group with appropriate properties promotes the desired hydrolysis–decarboxylation–decarbonylation sequence of reactions that leads to CO generation. One such CO prodrug was selected to recapitulate the anti-inflammatory effects of CO against LPS-induced TNF-α production in cell culture studies. Oral administration in mice elevated COHb levels to the safe and efficacious levels established in various preclinical and clinical studies. Furthermore, its pharmacological efficacy was demonstrated in mouse models of acute kidney injury. These studies demonstrate the potential of these prodrugs with benign carriers as orally active CO-based therapeutics. This represents the very first example of orally active organic CO prodrugs with a benign carrier that is an FDA-approved sweetener with demonstrated safety profiles in vivo.1,2-Dicarbonyl compounds with FDA-approved sweeteners as leaving groups deliver CO for protection against acute kidney injury in mice. 相似文献
46.
47.
G. M. Kalvius L. Asch D. R. Noakes R. Keitel J. H. Brewer E. J. Ansaldo F. J. Litterst B. Boucher J. Chappert A. Yaouanc T. Yamazaki K. Nagamine K. Nishiyama O. Hartmann R. Wäppling 《Hyperfine Interactions》1986,31(1-4):303-308
Crystalline (cr-) Dyag [CsC] structure] orders antiferro-magnetically with TN≅60K; amorphous (am-) DyAg ferro-magnetically with TC≈-18K. We measured the longitudinal field (LF) μ+SR relaxation functions GZZ(t) for 5K<T<300K using surface muons. In the paramagnetic state. cr-DyAg gives an exponential GZZ (t) in the relaxation rate rising first slowly then more rapidlynear TN; no decoupling is observed in LF up to 0.4T. In the ordered state we see a Lorentzian Kubo-Toyabe GZZ(t), becoming nearly static at the lowest temperatures. Its static width is very narrow (Δ≈-7 MHz), and full dceoupling is
achieved here in 0.1 T. On approaching TN, the fluctuation rate and the static width increase mootonically bt the field distribution remains Loratzian. A LF of 0.4T
is then insufficient to quench the fast exponential relaxation. In paramagnetic am-DyAg, the μ+ depolarization is always much faster then in cr-DyAg. At lower temperatures it is better described by a root-exponential
than an exponential GZZ(t). Below TC an exponentially relaxing signal with 1/3 amplitude is seen. The decoupling effect of LF up to 0.4T was negligible at all
temperatures. 相似文献
48.
R. F. Kiefl J. H. Brewer I. Affleck J. F. Carolan P. Dosanjh W. N. Hardy T. Hsu R. Kadono J. R. Kempton S. R. Kreitzman Q. Li A. H. O'Reilly T. M. Riseman P. Schleger P. C. E. Stamp H. Zhou L. P. Le G. M. Luke B. Sternlieb Y. J. Uemura H. R. Hart K. W. Lay 《Hyperfine Interactions》1991,63(1-4):139-144
We have searched for anomalous internal magnetic fields in highT
c materials which are predicted to occur in anyon and flux phase models of superconductivity. The magnitude, anisotropy and
temperature dependence of the observed fields inc-axis oriented samples of sintered YBa2CuO3O7 and of thick-film Bi2Sr2CaCu2O8 are consistent with a conventional nuclear dipolar origin. An upper limit of ≲0.08 mT is set for any anomalous magnetic fields
along thec-axis atμ
+ sites in bulk CuO2 superconductors. 相似文献
49.
Nb-silicide in situ composites have great potential for high-temperature turbine applications. Nb-silicide composites consist of a ductile Nb-based solid solution together with high-strength silicides, such as Nb5Si3 and Nb3Si. With the appropriate addition of alloying elements, such as Ti, Hf, Cr, and Al, it is possible to achieve a promising balance of room-temperature fracture toughness, high-temperature creep performance, and oxidation resistance. In Nb-silicide composites generated from metal-rich binary Nb-Si alloys, Nb3Si is unstable and experiences eutectoid decomposition to Nb and Nb5Si3. At high Ti concentrations, Nb3Si is stabilized to room temperature, and the eutectoid decomposition is suppressed. However, the effect of both Ti and Hf additions in quaternary alloys has not been investigated previously. The present article describes the discovery of a low-temperature eutectoid phase transformation during which (Nb)3Si decomposes into (Nb) and (Nb)5Si3, where the (Nb)5Si3 possesses the hP16 crystal structure, as opposed to the tI32 crystal structure observed in binary Nb5Si3. The Ti and Hf concentrations were adjusted over the ranges of 21 to 33 (at.%) and 7.5 to 33 (at.%) to understand the effect of bulk composition on the phases present and the eutectoid phase transformation. 相似文献
50.
S. A. Dodds T. L. Estle G. A. Gist Qiuan Zhu S. L. Rudaz D. P. Spencer E. J. Ansaldo J. H. Brewer D. R. Noakes R. Keitel 《Hyperfine Interactions》1986,32(1-4):869-872
Magnetic resonance of a spin system which is acted upon by a large near-resonance oscillating magnetic field transverse to
a static field has been studied experimentally and theoretically for many years. The technique of DEMUR (Double Electron Muon
Resonance) has many advantages for such studies. This paper will describe the results of an experiment to study the precession
of the muonium triplet near magnetic resonance using DEMUR. 相似文献