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排序方式: 共有399条查询结果,搜索用时 15 毫秒
181.
Patricia E. Simmons Tom Albers Debbie Barco Michelle Barker Ron Beer Cassandra Belton Betty Burris Hal Donovan Pili Dressel Ron Giesler Terri Gipson Neal Gleditsch Marian Heimbouch Lea Heintz Linda Kalinowski Kathy Ketterer Kit Klein Lebee Meehan Diane Miller Donna Northcott Barb Pollman Tom Potter Jeffrey Powell Dan Prater Doug Raney Chris Roman Beryl Rosenthal Brian Schaffer Joe Seidler Laura Sturmfels Mary Stewart Carey Tisdal Carol Valenta Suzanne Walton Ralph Wilke 《School science and mathematics》1998,98(7):354-356
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Injection of botulinum toxin (Botox) into the laryngeal muscleshas become the treatment of choice for controlling the symptoms of spasmodic dysphonia (SD). Currently, no specific battery of objective tests to assess the outcome is universally accepted. The purpose of this study was to investigate demographic, clinical, and treatment factors with voice outcome following Botox injection. Sixty-eight patients with adductor SD who underwent at least one Botox injection during a 5-year period were studied. Voice outcome measures were made from patient self-reporting scales and included overall vocal quality, length of response, and duration of breathiness. Vocal quality was significantly correlated with the underlying severity of vocal symptoms prior to treatment, incidence of breathiness and unilateral versus bilateral injection. The length of response was greater in males and following bilateral injections. An increased period of breathiness significantly correlated with bilateral injections. 相似文献
184.
Carol L. K. Sabourin Abbie G. Freeman Donna F. Kusewitt Ronald D. Ley 《Photochemistry and photobiology》1992,55(3):417-424
Chronic exposure of the gray, short-tailed oppossum, Monodelphis domestica to ultraviolet radiation (UVR) induces mesenchymal tumors of the cornea. High molecular weight DNA samples from 6 UVR-induced corneal tumors were assayed for their ability to transform NIH 3T3 cells to tumorigenicity. NIH 3T3 cells transfected with DNA from 5 of the corneal tumors produced 14 tumors in nude mice. Cell lines were established from these tumors. DNA from 13 of 14 tumor cell lines contained repetitive opossum DNA sequences. Southern blot analysis revealed that DNA from 3 of 4 cell lines derived from tumorigenic NIH 3T3 cells transfected with DNA from a single oppossum tumor contained opossum Ki-ras oncogene sequences in addition to the murine Ki-ras gene. Northern blot analysis of mRNA from a mouse tumor cell line containing opossum Ki-ras gene sequences showed mRNA species identical in size to opossum Ki-ras mRNA, as well as murine Ki-ras mRNA species. These results suggest that an activated Ki-ras oncogene was present in one of the original opossum corneal tumors tested. Thus, activation of Ki-ras may play a role in the development of UVR-induced corneal tumors in Monodelphis domestica. Further characterization of ras oncogenes in these opossum tumors may provide information on the molecular mechanisms by which UVR induces corneal tumors in this species. 相似文献
185.
Gabrielle A. Leith Allison M. Rice Brandon J. Yarbrough Anna A. Berseneva Richard T. Ly Charles N. Buck Denis Chusov Amy J. Brandt Donna A. Chen Benjamin W. Lamm Morgan Stefik Kenneth S. Stephenson Mark D. Smith Aaron K. Vannucci Perry J. Pellechia Sophya Garashchuk Natalia B. Shustova 《Angewandte Chemie (International ed. in English)》2020,59(15):6000-6006
The effect of donor (D)–acceptor (A) alignment on the materials electronic structure was probed for the first time using novel purely organic porous crystalline materials with covalently bound two‐ and three‐dimensional acceptors. The first studies towards estimation of charge transfer rates as a function of acceptor stacking are in line with the experimentally observed drastic, eight‐fold conductivity enhancement. The first evaluation of redox behavior of buckyball‐ or tetracyanoquinodimethane‐integrated crystalline was conducted. In parallel with tailoring the D‐A alignment responsible for “static” changes in materials properties, an external stimulus was applied for “dynamic” control of the electronic profiles. Overall, the presented D–A strategic design, with stimuli‐controlled electronic behavior, redox activity, and modularity could be used as a blueprint for the development of electroactive and conductive multidimensional and multifunctional crystalline porous materials. 相似文献
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187.
Anne E. Jenns Donna L. Scott Edmond F. Bowden Margaret E. Daub 《Photochemistry and photobiology》1995,61(5):488-493
Fungi in the genus Cercospora produce a singlet-oxygen-generating photosensitizing toxin cercosporin, which plays an important role in the ability of these fungi to parasitize plants. Previous studies demonstrated that resistance to cercosporin was associated with the ability of the fungus to reduce and detoxify cercosporin transiently. In order to characterize the mechanism of cercosporin resistance further, two types of mutants were isolated. One set of mutants was selected directly for sensitivity to cercosporin. Six cercosporin-sensitive mutants were isolated. Five of the mutants were totally inhibited by cercosporin as well as by five other photosensitizers, methylene blue, toluidine blue, eosin Y, rose bengal and hematoporphyrin. These five mutants were also deficient in cercosporin-reducing ability. The sixth cercosporin-sensitive mutant was only partially inhibited by cercosporin. This mutant was unaltered in cercosporin-reducing ability and in its response to the other photosensitizers. In order to test hypotheses concerning the mechanism of cercosporin reduction, a second set of mutants was selected for general deficiency in cell surface-reducing capability by screening for the inability to reduce two tetrazolium dyes (p-tolyltetrazolium red and 2,3,5-triphenyltetrazolium chloride) of similar redox potential to cercosporin. Dye-reduction-deficient mutants were unaltered in their resistance to cercosporin and in cercosporin-reducing ability. We conclude that cercosporin resistance of these fungi is strongly correlated with the ability to reduce cercosporin. However, cercosporin-reducing ability is separable from the general ability to reduce external electron acceptors. 相似文献
188.
Dr. Ivana Radivojevic Jovanovic Dr. Colleen M. B. Gallagher Ramsey Salcedo Hossam Elshendidi Dr. Jacopo Samson Dr. Charles M. Drain Dr. Donna McGregor Dr. Wayne W. Lukens Jr. Dr. Benjamin P. Burton-Pye Dr. Lynn C. Francesconi 《欧洲无机化学杂志》2023,26(1):e202200507
Technetium-99 is a prevalent fission product from nuclear waste. The long half-life (211,000 yr) and environmental mobility of pertechnetate (TcO4−) render Tc particularly challenging to isolate and stabilize. Here we present two approaches for development of potential wasteforms using titanium dioxide, TiO2. Approach 1 is a low temperature chemical synthesis of TiO2 doped with Tc(IV) from TcO4− intended to mimic the Tc waste stream from the UREX family of separations and removes 98.5 % of the Tc, mainly present as edge-shared Tc(IV) pairs. Approach 2 utilizes TiO2 to photocatalytically reduce TcO4− to Tc(IV) stabilized on the surface of or within the TiO2 lattice. The %Tc removed from solution and adsorbed to TiO2 is pH dependent, with the maximum Tc(IV) adsorbed at pH 3–4 as either TcO2 or edge-sharing Tc(IV) octahedra. The Tc(IV)-TiO2 composites materials formed by both approaches are suitable for consolidation into a dense wasteform by Hot Isostatic Pressing (HIPing). 相似文献
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190.
Donna S. Lundy Soham Roy Roy R. Casiano Jun W. Xue Joseph Evans 《Journal of voice》2000,14(4):490-493
The singing power ratio (SPR) is an objective means of quantifying the singer's formant. SPR has been shown to differentiate trained singers from nonsingers and sung from spoken tones. This study was designed to evaluate SPR and acoustic parameters in singing students to determine if the singer-intraining has an identifiable difference between sung and spoken voices. Digital audio recordings were made of both sung and spoken vowel sounds in 55 singing students for acoustic analysis. SPR values were not significantly different between the sung and spoken samples. Shimmer and noise-to-harmonic ratio were significantly higher in spoken samples. SPR analysis may provide an objective tool for monitoring the student's progress. 相似文献