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51.
52.
Downs Syndrome is a chromosomal disorder affecting approximately 1 in 700 live births in unscreened populations. Definitive prenatal diagnostic tests are available but they are invasive and can cause miscarriages. Non-invasive tests earlier in pregnancy have the potential for identifying pregnancies that are at sufficient risk to warrant the invasive diagnostic test being performed. A model has been developed to evaluate possible screening strategies. Although at first sight this problem seems amenable to traditional decision analysis, our alternative method has proved more fruitful. The method can be used to derive closed form analytical expressions for a number of relevant outcome measures. This modelling allows the study of the effect of the timings of the two tests within pregnancy, optimisation of screening options and investigation of effects related to diagnostic accuracy. 相似文献
53.
SUMMARY: A 52-year-old professional voice user, a director of international sales and marketing and sports coach, described a 40-year history of severe hoarseness, with recent progressive dysphonia. He could not be heard on a cell phone and was unable to raise the volume or intensity of his voice. Strobovideolaryngoscopy revealed a perplexing set of dual intracordal lesions in the left vocal fold and a posterior glottal gap. The amplitude and magnitude of the left vocal fold mucosal waves were barely perceptible and were severely decreased in the right. There was marked phase asymmetry and aperiodicity bilaterally. A computed tomography scan of the neck with contrast and multiplanar reformatted reconstructions and a magnetic resonance imaging (MRI) of the neck with and without contrast revealed the nodular appearing masses of the left vocal fold without any definite evidence of paraglottic or supraglottic extension and no cervical lymphadenopathy. He had a hyperfunctional larynx with laryngopharyngeal reflux and chronic reflux laryngitis. Voice restoration required antireflux therapy, voice therapy, and phonomicrosurgical excision of the lesions. One benign epidermoid malformation cyst was lined by squamous epithelium. The second was a retention cyst lined with cuboidal epithelium. Finally, after 40 years, he has a normal voice. 相似文献
54.
Gregory J. Gallivan 《Journal of voice》1991,5(4):338-348
Severe damage to the vocal folds and upper airways after translaryngeal endotracheal intubation occurs with greater frequency and to a greater extent than is usually surmised. Videolaryngoscopic techniques have led to prompt recognition of endolaryngeal/endotracheal lesions in the critical care setting. Traditionally, surgeons have treated obstructive sequelae such as glottic, subglottic, and tracheal stenosis by major transcervical and/or transthoracic resective and reconstructive surgery. Endolaryngeal core molds and endotracheal stents have conventionally been inserted by open surgical techniques. As a prototypic case illustrates, evolutional methods of endoscopic placement of prosthetic molds and stents combined with endoscopic optical/suction instrumentation and laser photoresection allow the physician to restore upper airway patency and phonatory vocal fold function without resorting to major surgery. Delta scan topograms provide radiographic imaging of the major airways. 相似文献
55.
This paper presents a model reduction method for large-scale linear systems that is based on a Lanczos-type approach. A variant of the nonsymmetric Lanczos method, rational Lanczos, is shown to yield a rational interpolant (multi-point Padé approximant) for the large-scale system. An exact expression for the error in the interpolant is derived. Examples are utilized to demonstrate that the rational Lanczos method provides opportunities for significant improvements in the rate of convergence over single-point Lanczos approaches. 相似文献
56.
V. Chabaud B. Hyams T. Papadopoulou K. Rybicki P. Weilhammer H. Becker G. Blanar M. Cerrada H. Dietl J. Gallivan B. Gottschalk E. Lorenz G. Lütjens G. Lutz W. Männer B. Niczyporuk D. Notz J. De Groot 《Nuclear Physics B》1980,175(2):189-196
We have studied A2? production by π? on a nuclear target in the K?KS0 decay channel, where the A2? is observed above a small background at 17.2 GeV/c incident momentum. Direct confirmation of coherent A2 (JP = 2+) production has been found. 相似文献
57.
Inhaled corticosteroids (ICS) have become the prevalent treatment in asthmatics. Hazards to voice are under-recognized. A total of 38 patients with voice complaints associated with the use of ICS were assessed by 79 strobovideolaryngoscopy (SVL) examinations, 24 single and 14 multiple SVL. Hoarseness and dysphonia were the primary reasons for referral. The ICS initially used most frequently was Advair Diskus (fluticasone propionate and salmeterol-inhalation powder-[IP]) in 22 patients, followed by Flovent (fluticasone propionate inhalation aerosol-pressurized metered-dose inhaler-[PMDI]) in 11. Duration of ICS usage varied from 2 weeks to 4-5 years. Higher dosage and frequency of use exacerbated problems. Hazards to voice previously unrecognized by real-time indirect mirror or fiberoptic laryngoscopy were identified by meticulous attention to SVL abnormalities. There was essentially no difference in occurrence of abnormalities whether analyzed from the perspective of the initial 38 or all 79 examinations. These included abnormal mucosal wave symmetry/periodicity (76-63%), phase closure (74-63%), glottic closure (63-59%), mucosal wave amplitude/magnitude (50-35%), supraglottic hyperactivity (39-25%), mucosal quality (34-34%), and glottic plane (10-5%).Candidiasis of the larynx was infrequently observed. Fluticasone ICS were a cause of steroid inhaler laryngitis, and the best treatment was their avoidance or cessation. Further prospective studies ideally might include SVL documented as a pretherapy baseline and then repeated in each ICS patient who developed hoarseness/dysphonia. 相似文献
58.
Bilateral Vocal Fold Posterior Glottic/Subglottic Stenotic Web Resected with Contact Tip Nd-YAG Laser 总被引:1,自引:0,他引:1
The standard treatment for respiratory failure remains endotracheal intubation, with periods of 22 or more days being commonplace. Posterior glottic stenotic web formation, from scarring in the posterior interarytenoid area, may occur after endotracheal intubation, thermal, corrosive, or direct surgical injury. A commonly used classification system for posterior glottic stenosis divides the occurrence into four types. Type I involves an interarytenoid scar band between the vocal folds that is anterior and separate from the posterior interarytenoid mucosa. Type II stenosis involves scarring of the mucosa or musculature of the posterior interarytenoid area. Types III and IV involve unilateral and bilateral cricoarytenoid joint fixation, respectively. Strobovideolaryngoscopy (SVL), rigid and flexible fiberoptic bronchoscopy, electromyography (EMG), radiologic imaging of the neck, larynx, and trachea as well as pulmonary function tests, including flow volume loops, provide important objective measurements of upper airway obstruction. A representative case of a professional voice user who suffered a Type II posterior glottic stenosis is presented. The treatment utilized a specific contact-tip neodymium-yttrium aluminum garnet (Nd-YAG) laser delivery system to achieve precise cutting, vaporization, and coagulation simultaneously, returning tactile touch technique to the airway/voice surgeon. Completely successful restoration of voice and airway have been maintained for 2 1/2 years postoperatively. 相似文献
59.
Topp S Prasad V Cianci GC Weeks ER Gallivan JP 《Journal of the American Chemical Society》2006,128(43):13994-13995
A major goal of polymer science is to develop "smart" materials that sense specific chemical signals in complex environments and respond with predictable changes in their mechanical properties. Here, we describe a genetic toolbox of natural and engineered protein modules that can be rationally combined in manifold ways to create reversible self-assembling materials that vary in their composition, architecture, and mechanical properties. Using this toolbox, we produced several materials that reversibly self-assemble in the presence of Ca2+ and characterized these materials using particle-tracking microrheology. The properties of these materials could be predicted from the dilute solution behavior of their component modules, suggesting that this toolbox may be generally useful for creating new stimuli-sensitive materials. 相似文献