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991.
BACKGROUND: Recently, investigators have reported the use of endoscopic myotomy in the treatment of esophageal achalasia. As with the open operation, considerable disagreement exists regarding the appropriate length of the myotomy and the need for a concomitant antireflux procedure. METHODS: Patients presenting with symptomatic achalasia between 1993 and 1997 were included in this prospective study. Preoperative studies included barium upper gastrointestinal study, endoscopy, and esophageal manometry. Laparoscopic myotomy was completed in all 20 patients; 18 had concomitant Toupet fundoplication. RESULTS: Operative times ranged from 95 to 345 minutes (mean 216). Blood loss ranged from 50 to 300 cc (mean 100 cc). There were 7 minor complications (5 mucosal injuries repaired laparoscopically, 1 bile leak and 1 splenic capsular tear). Nine patients began a liquid diet on the first day postoperatively; 19 were tolerating liquids by postoperative day 3. Hospital stay ranged from 2 to 20 days (mean 5). Eighteen patients had complete relief of dysphagia, with less than one reflux episode per month. One individual continues to have mild persistent solid food dysphagia. Another patient initially did well but subsequently developed mild recurrent dysphagia and reflux. One patient required laparoscopic take-down of the wrap because of recurrent dysphagia and now has no problems swallowing, but does complain of mild reflux. Two other patients also have mild reflux, 1 of whom did not undergo fundoplication. CONCLUSIONS: Laparoscopic Heller myotomy can be performed safely with excellent results in patients with achalasia. Adding a partial fundoplication appears to help control postoperative symptoms of reflux. This procedure should be considered the procedure of choice in patients with symptomatic esophageal achalasia. 相似文献
992.
L Canetti E Bachar E Galili-Weisstub AK De-Nour AY Shalev 《Canadian Metallurgical Quarterly》1997,32(126):381-394
Attachment between parent and child plays a crucial role in the healthy development of the child. Accordingly disturbances in parental bonding will be linked with the development of mental disorders later in life. The present study examines the relationship between parental bonding and mental health in healthy adolescents. Participants were 847 Israeli high school students who completed the Parental Bonding Instrument (PBI), the Brief Symptom Inventory (BSI), the General Well-Being (GWB), the Perceived Social Support (PSS), and the Social Desirability scale (SDS). In general, Israeli adolescents reported more parental care and less control than did Australian adolescents and adults. Female subjects reported more maternal care than did males. Subjects who reported high care and low control (optimal bonding) reported less distress, better general well-being and better social support that did all other groups. In contrast, those who reported low care and high control (affectionless control bonding) had the highest BSI scores and the lowest GWB and PSS scores. These results are in line with Bowlby's theory of attachment. They also show that specific configuration of parental bonding are linked with distress and isolation in adolescents. 相似文献
993.
994.
Measuring knowledge transfer between fields of science 总被引:4,自引:2,他引:2
Rinia Ed J. van Leeuwen Thed N. Bruins Eppo E. W. van Vuren Hendrik G. van Raan Anthony F. J. 《Scientometrics》2002,54(3):347-362
In this paper we report on the results of an exploratory study of knowledge exchange between disciplines and subfields of
science, based on bibliometric methods. The goal of this analysis is twofold. Firstly, we consider knowledge exchange between
disciplines at a global level, by analysing cross-disciplinary citations in journal articles, based on the world publication
output in 1999. Among others a central position of the Basic Life Sciences within the Life Sciences and of Physics within
the Exact Sciences is shown. Limitations of analyses of interdisciplinary impact at the journal level are discussed. A second
topic is a discussion of measures which may be used to quantify the rate of knowledge transfer between fields and the importance
of work in a given field or for other disciplines. Two measures are applied, which appear to be proper indicators of impact
of research on other fields. These indicators of interdisciplinary impact may be applied at other institutional levels as
well.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
995.
V. B. Baiburin Yu. P. Volkov E. M. Il’in S. V. Semenov 《Technical Physics Letters》2002,28(12):981-982
The surface of a palladium-barium cathode was studied using scanning probe microscopy techniques. Data from the tunneling spectroscopy showed the pattern of the electron work function distribution over a microscopic region on the emitter surface. This pattern is compared to the distribution of various phases in the palladium-barium alloy employed. 相似文献
996.
Laberteaux K.P. Rohrs C.E. Antsaklis P.J. 《Automatic Control, IEEE Transactions on》2002,47(6):960-978
This paper examines congestion control for explicit rate data networks. The available bit rate (ABR) service category of asynchronous transfer mode (ATM) networks serves as an example system, however, the results of this paper are applicable to other explicit rate systems as well. After a plant model is established, an adaptive control strategy is presented. Several algorithm enhancements are then introduced. These enhancements reduce convergence time, improve queue depth management, and reduce parameter bias. This work differentiates itself from the other contributions in the area of rate-based congestion control in its balanced approach of retaining enough complexity as to afford attractive performance properties, but not so much complexity as to make implementation prohibitively expensive 相似文献
997.
Formal Aspects of Computing are dedicated to Professor Rod Burstall, and, as a collection of papers, memoirs and incidental pieces, form a Festschrift
for Rod. The contributions are made by some of the many who know Rod and have been in uenced by him. The research papers included
here represent some of the areas in which Rod has been active, and the editors thank their colleagues for agreeing to contribute
to this Festschrift. 相似文献
998.
E. V. Astrova V. V. Ratnikov R. F. Vitman A. A. Lebedev A. D. Remenyuk Yu. V. Rud’ 《Semiconductors》1997,31(10):1084-1090
The results of an investigation of layers of porous silicon (PS), which was obtained by electrochemical etching of p-Si under different illumination conditions — natural light, incandescent light, and light from a mercury lamp with and without
a filter — are reported. The structure of the layers was studied by double-crystal x-ray diffractometry, the composition was
monitored by means of the IR absorption spectra, and the radiative properties were monitored according to the photoluminescence
(PL) spectra. It was established that electrochemical etching under illumination produces PS with a higher porosity and more
intense PL whose maximum is shifted into the short-wavelength region. These changes are accompanied by a large disordering
of the structure and an increase in the oxygen content in the layer. It is concluded that illumination accelerates the chemical
interaction of PS with the electrolyte due to oxidation. High-porosity porous silicon stored in air exhibits quenching of
PL. Conversely, PL is excited in layers with a lower porosity. Aging of PS is characterized by an increase in the microdeformation
of the layers, a decrease in the crystallite sizes with a partial loss of coherence between the crystallites and the substrate,
and an increase in the fraction of the amorphous phase.
Fiz. Tekh. Poluprovodn. 31, 1261–1268 (October 1997) 相似文献
999.
1000.
Hartung J. Jacquin A. Pawlyk J. Rosenberg J. Okada H. Crouch P.E. 《Selected Areas in Communications, IEEE Journal on》1998,16(1):42-55
This paper describes a prototype video coding platform meant for the conception and testing of multimedia products such as next-generation videophones. The platform is largely based on ITU-T Recommendation H.263, with a number of additional object-oriented quality enhancement features which make it especially well suited for very low bit-rate coding of “head-and-shoulders” video material typical of real-time multimedia applications, video teleconferencing, and video telephony. These features consist of: (1) segmentation into objects of interest, (2) segmentation-based prefiltering, (3) model-assisted rate control, (4) adaptive vector quantization, and finally (5) segmentation-based postfiltering. In the spirit of Recommendation H.263, these enhancements are modular and can be selectively turned on or off, thereby enabling a wide variety of coding modes 相似文献