8,357 research outputs found
Holomorphic isometries of Bm into bounded symmetric domains arising from linear sections of minimal embeddings of their compact duals
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Selection of patients of hepatocellular carcinoma beyond the Milan criteria for liver transplantation
The Milan criteria have been proven to be reliable and easily applicable in selection of patients with small unresectable hepatocellular carcinomas for liver transplantation. It has been repeatedly shown that patients who met these criteria had a 5-year survival of over 70% after transplantation. Such a result is remarkably good for an otherwise incurable malignancy. The main disadvantage of this set of criteria is that it is rather restrictive. Following it religiously denies transplantation to many patients who have tumor stage slightly more advanced. There have been many attempts to extend the criteria to include tumors with larger sizes (as in the UCSF criteria) or with a larger number (as in the Kyoto criteria). Alpha-fetoprotein and PIVKA-II, two biological markers in more aggressive tumors, have also been employed in the selection of patients, and biopsies have been used by the University of Toronto to determine tumor aggressiveness before deciding on transplantation. Patients with tumors beyond the Milan criteria yet not of a high grade have been accepted for transplantation and their survival is comparable to that of transplant recipients who were within the Milan criteria. Preoperative dual-tracer ((11)C-acetate and FDG) positron emission tomography has been used to determine tumor grade, and transarterial chemoembolization has been used to downstage tumors, rendering them meeting the Milan criteria. Patients with downstaged tumors have excellent survival after transplantation. Partial response to chemical treatment is a reflection of less aggressive tumor behavior. Careful selection of patients beyond the Milan criteria with the aid of serum tumor marker assay, positron emission tomography or tumor biopsy allows transplanting more patients without compromising survival. The use of liver grafts either from the deceased or from living donors could thus be justified.published_or_final_versio
Late recurrence of hepatocellular carcinoma after liver transplantation
Background: Long-term survival of patients with hepatocellular carcinoma (HCC) after liver transplantation is affected mainly by recurrence of HCC. There is the opinion that the chance of recurrence after 2 years post-transplantation is remote, and therefore lifelong surveillance is not justified because of limited resources. The aims of the present study were to determine the rate of late HCC recurrence (≥2 years after transplantation) and to compare the long-term patient survival outcomes between cases of early recurrence (<2 years after transplantation) and late recurrence. Patients: A total of 139 adult HCC patients having liver transplantation during the period from July 1994 to December 2007 were included in the analysis. The median follow-up period was 55 months. Thirty-two patients received deceased-donor grafts and 107 received living-donor grafts. Results: Hepatocellular carcinoma recurrence occurred in 24 (17.3%) patients, among them 22 (86%) had living-donor grafts and 7 (5%) developed late recurrence. Patients in the early recurrence group and patients in the late recurrence group had comparable demographics and disease pathology. The former group, when compared with the latter, had significantly worse overall survival at 3 years (13.3 versus 100%) and 5 years (6.67 versus 71.4%) (log-rank test; p < 0.001). Conclusions: Both early recurrence and late recurrence of HCC after liver transplantation were not uncommon, mostly detected at a subclinical stage. Regular and long-term surveillance with imaging and blood tests is essential for early detection. © 2011 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201
Ultrasonic hydrophone based on distributed Bragg reflector fiber laser
2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Behaviour of jacked and driven piles in sandy soil
As an alternative to conventional dynamic pile installation methods, pile jacking is an environmentally friendly technique that could become more widely accepted. Great concern has arisen over the performance of jacked piles as compared with that of driven piles. This paper describes a comprehensive field study that was aimed at investigating the differences and similarities between the behaviour of jacked H-piles and that of driven H-piles. The instrumented piles, varying in length from 32 to 55 m and having a design capacity of up to 3540 kN, were installed in residual soils whose properties are close to silty sands. The load test results indicate that the shaft resistance of jacked piles is generally suffer and stronger than that of driven piles, but the base resistance of jacked piles is weaker than that of driven piles. At a load level of twice the design capacity, the percentage of pile head load carried by base varies from 2% to 10% for jacked piles, with a mean value of 6%; for driven piles the percentage varies from 6% to 61% with a mean value of 38%. The back-calculated values of the shaft friction coefficient, β, were found to be in a range of 0.25-0.6 for both jacked and driven piles. A correlation was also observed between the ultimate shaft friction and the mean standard penetration test N value (N̄), which suggests that the shaft friction can be taken as 1.5N̄ to 2N̄ (kPa) for both jacked and driven H-piles.published_or_final_versio
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