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排序方式: 共有2056条查询结果,搜索用时 15 毫秒
31.
OBJECTIVE: To determine whether maintenance therapy can be discontinued safety in patients with quiescent cytomegalovirus retinitis (CMVR) and increased CD4+ counts after treatment with highly active antiretroviral therapy (HAART). DESIGN: A prospective observational case series. PARTICIPANTS: Eight human immunodeficiency virus (HIV)-positive patients with quiescent CMVR who were taking HAART and had CD4+ counts above 100 cells/microliter elected to discontinue anti-CMV maintenance treatment. INTERVENTION: Biweekly-to-monthly indirect ophthalmoscopy and fundus photographs, monthly-to-quarterly CD4+ counts, and quarterly HIV viral loads were ordered. MAIN OUTCOME MEASURES: Twelve previously affected eyes were examined for evidence of recurrent retinitis, which was defined as any retinal whitening, border opacification, or expansion of areas of retinal pigment epithelial (RPE) atrophy greater than 750 microns. Four previously unaffected fellow eyes were observed for new CMVR. RESULTS: There was no reactivation or progression of retinitis in any patient during the mean follow-up interval of 11.4 months (range, 3-16 months). No previously unaffected eye developed CMVR. CD4+ remained elevated in all patients (range, 70-725; mean, 255). The HIV viral load ranged from undetectable to 139,000 copies. CONCLUSION: Discontinuation of maintenance therapy may be considered in patients with HAART-induced elevated CD4+ counts above 100 cells/microliter, prolonged relapse-free intervals during the reconstitution period before CD4+ counts rise above 100 cells/microliter, and completely quiescent retinitis characterized by RPE scarring only. Reduced risks of drug toxicity and drug-resistant organisms are potential benefits. Close observation for evidence of recurrent retinitis is indicated. 相似文献
32.
N Qvist E Oster-J?rgensen SA Pedersen L Rasmussen 《Canadian Metallurgical Quarterly》1996,41(5):835-839
Fasting gastrointestinal motility and gallbladder motility during the interdigestive state and in the postprandial period was studied in eight patients who were operated for ulcer disease with an antrectomy and selective gastric vagotomy. Nocturnal motility recording revealed all three phases of the migrating motor complex (MMC) in all but one patient, where no phase III activity was recorded. In the rest of the patients 3-10 events with phase III activity were recorded. At scintigraphy ([75Se]HCAT) a cyclic gallbladder filling and emptying in relation to the MMC cycle was found. Episodes with emptying were confined to phase II and a total of 13 episodes with a median duration of 25 min (range 10-70 min) were observed. A median of 10.7% (6.1-17.7%) of the gallbladder contents was emptied. In a control group of eight healthy young men the values were 13.5 min (9-36 min) and 6.9% (3.7-31.1%), respectively. These differences were not significant. During the postprandial period, a lag period in gallbladder emptying of median 15 min (5-20 min) was observed when food ingestion took place during phase I of the MMC. Thereafter a gradual emptying occurred with a rate of 0.95% min (0.71-1.15%/min). In a control group of healthy young males, the lag period was 13.5 min (9-22.5 min) and the emptying rate 0.61%/min (0.08-0.77%/min). When food ingestion occurred during phase II of the MMC, the lag period of gallbladder emptying in the patient group was median 0 min (0-5 min) and the emptying rate was 0.77%/min (0.33-0.86%/min). The values in the control group were 0 min (-9 to 13.5 min) and 0.76%/min (0.54-2.25%/min), respectively. These differences between the patients and controls were not significant. In conclusion, antrectomy and selective gastric vagotomy do not influence fasting gastrointestinal motility or gallbladder motility during the interdigestive state or in the postprandial period. 相似文献
33.
MS McNeill DB Griffin TR Dockerty JP Walter HK Johnson JW Savell 《Canadian Metallurgical Quarterly》1998,76(6):1613-1620
Twenty-nine selected styles of subprimals or sections of veal were obtained from a commercial facility to assist in the development of a support program for retailers. They were fabricated into bone-in or boneless retail cuts and associated components by trained meat cutters. Each style selected (n = 6) was used to generate mean retail yields and labor requirements, which were calculated from wholesale and retail weights and processing times. Means and standard errors for veal ribs consisting of five different styles (n = 30) concluded that style #2, 7-rib 4 (10 cm) x 4 (10 cm), had the lowest percentage of total retail yield (P < .05) owing to the greatest percentage of bone. Furthermore, rib style #2 required the longest total processing time (P < .05). Rib styles #3, 7-rib chop-ready, and #5, 6-rib chop ready, yielded the greatest percentage of total retail yield and also had the shortest total processing time (P < .05). Within veal loins, style #2, 4 (10 cm) x 4 (10 cm) loin kidney fat in, had the greatest percentage fat (P < .05). Loin styles #2 and #3, 4 (10 cm) x 4 (10 cm) loin special trimmed, generated more lean and fat trimmings and bone, resulting in lower percentage of total retail yields than loin style #1, 0 (0 cm) x 1 (2.5 cm) loin special trimmed (P < .05). Results indicated that bone-in subprimals and sections required more processing time if fabricated into a boneless end point. In addition, as the number of different retail cuts increased, processing times also increased. 相似文献
34.
MA Piplani DG Disler TR McCauley TJ Holmes JP Cousins 《Canadian Metallurgical Quarterly》1996,198(3):855-859
PURPOSE: To determine the accuracy of semiautomated quantification of articular cartilage volume from three-dimensional (3D) reformations of magnetic resonance (MR) images. MATERIALS AND METHODS: Sagittal, fat-suppressed, 3D, spoiled gradient-recalled-echo MR imaging of two bovine and two human cadaver knees was performed. Articular cartilage volume was calculated from 3D reformations of the MR images by using a semiautomated program written at the authors' institution. Calculated volumes were compared with directly measured volumes of the surgically removed articular cartilage. RESULTS: The percentage of error of the MR imaging-determined volumes was 6.53% +/- 4.75 (mean +/- standard deviation). A strong correlation between the two sets of observations was shown (r=.997). Linear regression showed the calculated volumes to be highly accurate (slope=1.002, P>.25). Repeated reformations yielded volumes that were reproducible (mean absolute error, 0.013 mL +/- 0.019) and not significantly different from the measured volume (P>.10). CONCLUSION: Semiautomated quantification of knee articular cartilage from MR images yields highly accurate cartilage volumes. 相似文献
35.
Ana Ribeiro John Rasmussen Paulo Flores Luís F. Silva 《Multibody System Dynamics》2012,28(1-2):181-197
The development of a computational multibody knee model able to capture some of the fundamental properties of the human knee articulation is presented. This desideratum is reached by including the kinetics of the real knee articulation. The research question is whether an accurate modeling of the condyle contact in the knee will lead to reproduction of the complex combination of flexion/extension, abduction/adduction, and tibial rotation observed in the real knee. The model is composed by two anatomic segments, the tibia and the femur, whose characteristics are functions of the geometric and anatomic properties of the real bones. The biomechanical model characterization is developed under the framework of multibody systems methodologies using Cartesian coordinates. The type of approach used in the proposed knee model is the joint surface contact conditions between ellipsoids, representing the two femoral condyles, and points, representing the tibial plateau and the menisci. These elements are closely fitted to the actual knee geometry. This task is undertaken by considering a parameter optimization process to replicate experimental data published in the literature, namely that by Lafortune and his coworkers in 1992. Then kinematic data in the form of flexion/extension patterns are imposed on the model corresponding to the stance phase of the human gait. From the results obtained, by performing several computational simulations, it can be observed that the knee model approximates the average secondary motion patterns observed in the literature. Because the literature reports considerable inter-individual differences in the secondary motion patterns, the knee model presented here is also used to check whether it is possible to reproduce the observed differences with reasonable variations of bone shape parameters. This task is accomplished by a parameter study, in which the main variables that define the geometry of condyles are taken into account. It was observed that the data reveal a difference in secondary kinematics of the knee in flexion versus extension. The likely explanation for this fact is the elastic component of the secondary motions created by the combination of joint forces and soft tissue deformations. The proposed knee model is, therefore, used to investigate whether this observed behavior can be explained by reasonable elastic deformations of the points representing the menisci in the model. 相似文献
36.
Christopher Rasmussen 《Autonomous Robots》2008,25(3):205-229
We present a vision- and ladar-based approach to autonomous driving on rural and desert roads that has been tested extensively
in a closed-loop system. The vision component uses Gabor wavelet filters for texture analysis to find ruts and tracks from
which the road vanishing point can be inferred via Hough-style voting, yielding a direction estimate for steering control.
The ladar component projects detected obstacles along the road direction onto the plane of the front of the vehicle and tracks
the 1-D obstacle “gap” presumed due to the road to yield a lateral offset estimate. Several image- and state-based tests to
detect failure conditions such as off-road poses (i.e., there is no road to follow) and poor lighting due to sun glare or
distracting shadows are also explained. The system’s efficacy is demonstrated with analysis of diverse logged data including
from the 2005 DARPA Grand Challenge, as well as tests with full control of a vehicle over 15 km of difficult roads at up to
37 km/h with no waypoints.
相似文献
Christopher RasmussenEmail: |
37.
SD Colman SA Rasmussen VT Ho CR Abernathy MR Wallace 《Canadian Metallurgical Quarterly》1996,58(3):484-490
Using loss of heterozygosity analysis, a method designed to detect moderate to large gene deletions, we have identified a new-mutation neurofibromatosis type 1 (NF1) patient who is somatically mosaic for a large maternally derived deletion in the NF1 gene region. The deletion extends at least from exon 4 near the 5' end of the gene to intron 39 near the 3' end. The gene-coding region is, therefore, mostly or entirely deleted, encompassing a loss of > or = 100 kb. We hypothesize that the deletion occurred at a relatively early developmental timepoint, since signs of NF1 in this patient are not confined to a specific body region, as seen in "segmental" NF, and since both mesodermally and ectodermally derived cells are affected. This report provides the first molecular evidence of somatic mosaicism in NF1 and, taken together with a recent report of germ-line mosaicism in NF1, adds credence to the concept that mosaicism plays an important role in phenotypic and genetic aspects of NF1 and may even be a relatively common phenomenon. 相似文献
38.
Simon Richard Proud Mads Olander Rasmussen Inge Sandholt Wycliffe Mutero Assaf Anyamba 《Remote sensing of environment》2010,114(8):1687-1698
In order to obtain high quality data, the correction of atmospheric perturbations acting upon land surface reflectance measurements recorded by a space-based sensor is an important topic within remote sensing. For many years the Second Simulation of the Satellite Signal in the Solar Spectrum (6S) radiative transfer model and the Simplified Method for Atmospheric Correction (SMAC) codes have been used for this atmospheric correction, but previous studies have shown that in a number of situations the quality of correction provided by the SMAC is low. This paper describes a method designed to improve the quality of the SMAC atmospheric correction algorithm through a slight increase in its computational complexity. Data gathered from the SEVIRI aboard Meteosat Second Generation (MSG) is used to validate the additions to SMAC, both by comparison to simulated data corrected using the highly accurate 6S method and by comparison to in-situ and 6S corrected SEVIRI data gathered for two field sites in Africa. The additions to the SMAC are found to greatly increase the quality of atmospheric correction performed, as well as broaden the range of atmospheric conditions under which the SMAC can be applied. When examining the Normalised Difference Vegetation Index (NDVI), the relative difference between SMAC and in-situ values decreases by 1.5% with the improvements in place. Similarly, the mean relative difference between SMAC and 6S reflectance values decreases by a mean of 13, 14.5 and 8.5% for Channels 1, 2 and 3 respectively. Furthermore, the processing speed of the SMAC is found to remain largely unaffected, with only a small increase in the time taken to process a full SEVIRI scene. Whilst the method described within this paper is only applicable to SEVIRI data, a similar approach can be applied to other data sources than SEVIRI, and should result in a similar accuracy improvement no matter which instrument supplies the original data. 相似文献
39.
Rasmussen CD Jørgensen MB Carneiro IG Flyvholm MA Olesen K Søgaard K Holtermann A 《Ergonomics》2012,55(2):256-264
Worksite health promotion is seldom offered to workers who are low-educated and multi-ethnic, possibly due to an assumption that they are more reluctant to participate. Furthermore, little has been done to promote health at female-dominated workplaces. The main aim of this study was to investigate differences in participation among immigrant and Danish cleaners throughout a 1-year randomised controlled study tailored to cleaners and carried out in predominantly female workplaces. No significant differences in ethnicity were found in consent and participation throughout the 1-year intervention. Dropout was equally distributed among Danish and immigrant cleaners. This study indicates that a worksite health promotion intervention among a female-dominated, high-risk occupation such as cleaning can be equally appealing for Danes and immigrants. PRACTITIONER SUMMARY: This study provides insight about participation of Danish and immigrant cleaners in a worksite health promotion intervention in a predominantly female occupation. For attaining high participation and low dropout in future worksite health promotion interventions among cleaners, the intervention ought to not only target the ethnic background of the workers, but also to be specifically tailored to the job group. 相似文献
40.
Terminal chromosome associations ("satellite associations") in ASG-banded preparations have been used to determine the number and location of staellites in the Syrian hamster (Mesocricetus auratus) and the Djungarian hamster (Phodopus sungorus). Five pairs of satellites are found in the former and four in the latter. Nucleolar organizing regions (NORs) were visualized with the Ag-AS silver precipitation technique, and their number and position corresponded exactly with the number and position of satellites in Phodopus, where positive chromosome identification can be made in the absence of banding. Numerical agreement is exact in Mesocricetus as well, and the morphology of the silver-tagged NOR-bearing chromosomes strongly suggests that corrrespondence also occurs in this species. 相似文献