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1.
Although European treatises were translated and available to American doctors interested in neurology during the 19th century, the early American neurologic textbooks were distinctive in their comprehensive integration of basic and clinical science. William A. Hammond, in 1871, published the first comprehensive American textbook of neurology, preceding the manuals by Gowers (1886) and Oppenheim (1894) by more than a decade. Four other American adult neurologic textbooks expanded on Hammond's model and incorporated other important topics, including neurologic anatomy, the formal examination, neurochemistry, and complete bibliographies. Bernard Sachs' 1895 textbook was the first pediatric neurologic textbook published in America and made significant contributions to the organization of childhood neurologic disorders. These works functioned as centralized resources for neurologic information, were influential educational tools, and helped foster a growing appreciation of the American neurologic school both nationally and internationally. 相似文献
2.
EJ Pappert CG Goetz FG Niederman R Raman S Leurgans 《Canadian Metallurgical Quarterly》1999,14(1):117-121
Middle ear effusion has been considered the most common cause of vestibular disturbance in children. However, there have been only a few studies on vestibular disturbance in children with otitis media with effusion. We studied the vestibular systems of 30 children with otitis media with effusion aged 8 to 13 years and compared the results with 15 age- and sex-matched controls. A questionnaire relating to vestibular disturbance was given to patients and their parents. Spontaneous nystagmus and positional nystagmus were recorded by electronystagmography as diagnostic tests of the vestibular system. Romberg's and past-pointing tests were performed on children with otitis media with effusion and controls. After vestibular tests were completed, myringotomy was performed, and a ventilation tube was inserted. The questionnaire and the vestibular tests were repeated after the operation and during the first month after surgery. Our study showed that there was a history of vestibular disturbance in 33% of children with otitis media with effusion. Electronystagmography and Romberg's test findings demonstrated that 33% of the children had vestibular dysfunction (p < 0.05). After myringotomy with ventilation tube insertion, vestibular test results returned to normal, and symptoms related to vestibular disturbance improved. These findings confirm the assumption that middle ear effusion may affect the vestibular system, which can be resolved after myringotomy with ventilation tube insertion. 相似文献
3.
Dipole segmentation is used to estimate the radiation resistance of thin antennas of arbitrary elevation and configuration over a perfectly conducting ground plane. Utility of the method for estimating the radiation resistance of VLF/LF trailing wire antennas from aircraft depends upon the extent to which the current distribution deviates from a sinusoid. That deviation is due in part to finite wire thickness as well as the finite conductivity of both wire and ground. The influence of those effects requires further study. 相似文献
4.
Tsui P.G.Y. Pappert B. Sun S.W. Yeargain J.R. 《Solid-State Circuits, IEEE Journal of》1993,28(3):371-374
A simple BiCMOS configuration employing the source-well tie PMOS/n-p-n pull-down combination is proposed for low-voltage, high-performance operations. The improved BiCMOS gate delay time over that of the NMOS/n-p-n (conventional) BiCMOS gate is confirmed by means of inverter simulations and measured ring oscillator data. The source-well tie PMOS/n-p-n BiCMOS gate outperforms its conventional BiCMOS counterpart in the low-voltage supply range, at both high and low temperatures. A critical speed path from the 68030 internal circuit is used as a benchmark for the proposed BiCMOS design technique. The measured propagation delay of the BiCMOS speed path is faster than its CMOS counterpart down to 2.3 V supply voltage at -10°C and sub-2 V at 110°C 相似文献
5.
Li G.L. Pappert S.A. Mages P. Sun C.K. Chang W.S.C. Yu P.K.L. 《Photonics Technology Letters, IEEE》2001,13(10):1076-1078
High-saturation power traveling-wave electroabsorption modulators (TW-EAMs) with modulation bandwidth greater than 40 GHz have been demonstrated. Microwave properties of the TW-EAM waveguide are extracted from the measured S-parameters using an equivalent circuit model. Excellent agreement is obtained between the predicted and the measured frequency responses 相似文献
6.
J M?urer A Kendzia H Gerlach D Pappert J Hierholzer KJ Falke R Felix 《Canadian Metallurgical Quarterly》1998,24(11):1152-1156
The value of ultrasonography (US), magnetic resonance imaging (MRI), computed tomography (CT) and plain radiography (PR) in detecting bone erosions on the humeral head was evaluated in a study of 26 in-patients (26 shoulders) with rheumatoid arthritis (RA). MRI depicted humeral erosions in 25 (96%), US in 24 (92%), CT in 20 (77%) and PR in 19 (73%) of the 26 shoulders. MRI and US were superior to CT in detecting small erosions. US was the most sensitive method to show surface erosions on the greater tuberosity. US, CT and MRI detected large erosions quite similarly. PR frequently missed small erosions. In the evaluation of early erosions in the rheumatoid shoulder, US and MRI are more sensitive methods than the traditionally used PR. US and MRI are suitable for the evaluation of soft-tissue involvement in the rheumatoid shoulder, but also for the detection of bone erosions of the humeral head. 相似文献
7.
EJ Pappert CG Goetz F Niederman ZD Ling GT Stebbins PM Carvey 《Canadian Metallurgical Quarterly》1996,47(6):1493-1495
We performed the first double-blind, crossover comparison between levodopa/carbidopa (LD/CD) in optimized liquid versus tablet doses to measure plasma LD levels and relative effects on disabilities (motor function, fluctuations, and dyskinesias) in patients with Parkinson's disease. Twenty-three subjects with motor fluctuations were optimized with open-label LD/CD tablets and liquid. In a double-dummy design, patients randomly received 2 weeks of liquid and 2 weeks of tablet LD/CD. Twice during each arm, we evaluated patients hourly 9 AM to 4 PM with the use of plasma LD levels, the Unified Parkinson's Disease Rating Scale, a dyskinesia rating scale, and "on-off" ratings. Patients receiving liquid LD/CD ingested significantly higher doses and had significantly improved motor function and total "on" time, without an increase in dyskinesia severity. The number of motor fluctuations in the two phases was not significantly different. LD levels and variability were also equivalent with the two formulations. At optimized dosing, liquid LD/CD offers a means to significantly improve motor disability in patients with Parkinson's disease without exacerbating dyskinesia. 相似文献
8.
C. Gould K. Pappert G. Schmidt L. W. Molenkamp 《Advanced materials (Deerfield Beach, Fla.)》2007,19(3):323-340
In this Review, we discuss the rich anisotropic properties of the ferromagnetic semiconductor (Ga,Mn)As, and their implications in transport studies. We review the various sources and types of anisotropy seen in the material, discuss its magnetization reversal process, and demonstrate how basic transport properties, such as resistivity and Hall measurements, can be used as very sensitive tools to investigate the magnetization properties of the material. We also discuss how the magnetic anisotropy, coupled with large spin–orbit coupling, leads to an anisotropy in the transport density of states, which in turn leads to fundamentally novel behavior such as tunneling anisotropic magnetoresistance (TAMR). 相似文献
9.
Pappert S.A. Orazi R.J. Vu T.T. Lin S.C. Clawson A.R. Yu P.K.L. 《Photonics Technology Letters, IEEE》1990,2(4):257-259
A ridge-waveguide In0.53Ga0.47As/InP multiple-quantum-well (MQW) electroabsorption modulator operating at a wavelength of 1.52 μm is demonstrated. The modulator exhibits large polarization-dependent electroabsorption behavior which favors the modulation of the TM mode. At a reverse bias of 10 V, the modulator has a 24.5-dB extinction ratio for the TM mode, whereas that for the TE mode is only 11.1 dB. Polarization-dependent saturation of absorption has been observed in this device for incident optical power levels of less than 1 mW 相似文献
10.
Propagation theory along the lines of Budden's terrestrial waveguide formalism is reviewed. Special emphasis is placed on its application to the lower extremely low frequency (ELF) range for which a number of calculations have been made to demonstrate the relationship between propagation parameters and the physical constants of the ionosphere. Calculations performed with diffuse anisotropic ionospheres yield reasonable agreement with ELF test results. 相似文献