Unknown Location (unknown + location)

Distribution by Scientific Domains

Selected Abstracts

A Dynamic Analysis of a Spatial Manipulator to Determine Payload Weight

Carl D. Crane III
This paper presents a methodology whereby the payload weight of a serial manipulator can be determined from a minimum set of sensor data, i.e., joint angle and joint torque measurements. The particular manipulator geometry that is analyzed is a four degree-of-freedom serial chain that is commonly used in excavator systems. It was quite remarkable that a relatively simple solution was obtained for the payload weight considering that there are a total of nine unknown moments and cross moments of inertia of the payload together with the unknown location of the center of mass. Example calculations are presented. © 2003 Wiley Periodicals, Inc. [source]

Extent of pelvic lymphadenectomy in women with squamous cell carcinoma of the uterine cervix: Is there any prognostic value?

Josť Humberto Tavares Guerreiro Fregnani MD
Abstract Background and Objectives Some authors states that the removal of lymph node would only contribute towards assessing the lymph node status and regional disease control, without any benefit for the patients' survival. The aim of this paper was to assess the influence of the number of surgically dissected pelvic lymph nodes (PLN) on disease-free survival. Methods Retrospective cohort study on 42 women presenting squamous cell carcinoma (SCC) of the uterine cervix, with metastases in PLN treated by radical surgery. The Cox model was used to identify risk factors for recurrence. The model variables were adjusted for treatment-related factors (year of treatment, surgical margins and postoperative radiotherapy). The cutoff value for classifying the lymphadenectomy as comprehensive (15 PLN or more) or non-comprehensive (<15 PLN) was determined from analysis of the ROC curve. Results Fourteen recurrences (32.6%) were recorded: three pelvic, eight distant, two both pelvic and distant, and one at an unknown location. The following risk factors for recurrence were identified: invasion of the deep third of the cervix and number of dissected lymph nodes <15. Conclusions Deep invasion and non-comprehensive pelvic lymphadenectomy are possible risk factors for recurrence of SCC of the uterine cervix with metastases in PLN. J. Surg. Oncol. 2009;100:252,257. © 2009 Wiley-Liss, Inc. [source]

General obstetrics: Failing pregnancies of unknown location: a prospective evaluation of the human chorionic gonadotrophin ratio

G Condous
Objective, To assess the performance of the human chorionic gonadotrophin (hCG) ratio (hCG 48 hours/hCG 0 hour) to predict spontaneous resolution of pregnancies of unknown location (PUL). Design, Prospective cohort study. Setting, Teaching Hospital Early Pregnancy Unit. Population, Women classified as having a PUL. Methods, The optimal cutoff value for hCG ratio (serum hCG at 48 hours/serum hCG at 0 hours) was calculated from data on 189 consecutive PULs (the ,training set'). This cutoff was tested prospectively on a further 200 consecutive PULs (the ,test set'). The hCG ratio was also compared to absolute levels of serum hCG at 0 and 48 hour for the prediction of failing PULs. Main outcome measures, hCG ratio in spontaneously resolving (,failing') PUL compared with those requiring intervention. Optimum cutoff determined and tested to predict spontaneously resolving PUL. Comparison of hCG ratio with absolute levels of serum hCG. Results, A total of 3996 consecutive women were scanned, of which 438 (11.0%) were classified as PULs. Complete data were available for 389 women: 189 in the training set and 200 in the test set. In the training set, there were 102 (54%) failing PUL, while 109 (55%) in the test set. hCG ratio of <0.87 predicted failing PUL, with a sensitivity of 93.1% (95% CI 85.9,97.0) and a specificity of 90.8% (95% CI 82.2,95.7) in the training set. In the test set, sensitivity was 92.7% (95% CI 85.6,96.5) and specificity was 96.7% (95% CI 90.0,99.1). The hCG ratio outperformed absolute serum hCG levels at 0 and 48 hours. Conclusions, We have defined the optimal hCG ratio for the prediction of failing PUL. Using this cutoff, clinicians can safely adopt a noninterventional approach in women with PUL. [source]