59 research outputs found
Preoperative estimation of remnant hepatic function by fusion images of CT scans and single photon emission CT (SPECT) using 99mTc-GSA.
BACKGROUND:
Assessment of hepatic functional reserve is important in hepatic resection. The aim of this study was to evaluate the role of hepatic asialoglycoprotein receptor (ASGP-R) analysis in the preoperative estimation of remnant liver function in liver surgery.
METHODS:
One hundred and one patients undergoing hepatic resection for liver tumours were studied. Seventeen patients had preoperative percutaneous transhepatic portal vein embolization (PTPE). Function of the hepatic remnant was estimated before surgery using radioactivity in fusion images of both liver single-photon emission computed tomography and computed tomography scans using (99m)Tc-labelled diethylene triamine penta-acetate-galactosyl-human serum albumin.
RESULTS:
All three patients with an ASGP-R concentration below 400 nmol/l and preoperative total amount of receptor in the future remnant liver (R0-remnant) of less than 53.0 nmol per liver died. Two patients with chronic hepatitis and R0-remnant values between 53.0 and 65.0 nmol per liver and a receptor concentration lower than 600 nmol/l developed liver dysfunction. The incidence of liver failure decreased inversely with increasing R0-remnant value.
CONCLUSION:
A combination of receptor concentration and the amount of hepatic receptor in the future liver remnant as detected on fusion images is useful in evaluating the risk of postoperative liver failure
Photoemission from the gas phase using soft x-ray fs pulses: An investigation of the space-charge effects
An experimental and computational investigation of the space-charge effects
occurring in ultrafast photoelectron spectroscopy from the gas phase is
presented. The target sample CFI is excited by ultrashort (100 fs)
far-ultraviolet radiation pulses produced by a free-electron laser. The
modification of the energy distribution of the photoelectrons, i.e. the shift
and broadening of the spectral structures, is monitored as a function of the
pulse intensity. A novel computational approach is presented in which a survey
spectrum acquired at low radiation fluence is used to determine the initial
energy distribution of the electrons after the photoemission event. The
spectrum modified by the space-charge effects is then reproduced by -body
calculations that simulate the dynamics of the photoelectrons subject to the
mutual Coulomb repulsion and to the attractive force of the positive ions. The
employed numerical method allows to reproduce the complete photoelectron
spectrum and not just a specific photoemission structure. The simulations also
provide information on the time evolution of the space-charge effects on the
picosecond scale. Differences with the case of photoemission from solid samples
are highlighted and discussed. The presented simulation procedure constitutes
an effective tool to predict and account for space-charge effect in
time-resolved photoemission experiments with high-intensity pulsed sources.Comment: 18 pages, 4 figures, 1 tabl
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Evidence for Efficient Pathway to Produce Slow Electrons by Ground-state Dication in Clusters
We present an experimental evidence for a so-far unobserved, but potentially very important step relaxation cascades following inner-shell ionization of a composite system: Multiply charged ionic states created after Auger decay may be neutralized by electron transfer from a neighboring species, producing at the same time a low-energy free electron. This electron transfer-mediated decay (ETMD) called process is effective even after Auger decay into the dicationic ground state. Here, we report the ETMD of Ne2+ produced after Ne 1s photoionization in Ne-Kr mixed clusters
Preparation of anti-decay self-setting pastes of hydroxyapatite/collagen utilizing (3-glycidoxypropyl)trimethoxysilane
This article describes preparation of anti-decay self-setting pastes of hydroxyapatite/collagen (HAp/Col) utilizing (3-glycidoxypropyl)trimethoxysilane (GPTMS). The powder portion of the paste was ball-milled HAp/Col synthesized by the simultaneous titration method, and the liquid portion was GPTMS aqueous solution at a concentration of 0.1, 1.0 or 10 % in volume. The HAp/Col-GPTMS pastes were prepared by mixing the powder and liquid portions at powder/liquid (P/L) ratios ranging from 0.20 to 2.00 (g/cm3). The pastes with P/L ratios from 0.33 to 1.50 showed good handling properties, and their viscosities depended greatly on the P/L ratio. The lowest washout ratio was observed at a P/L ratio of 1.00 independent of the GPTMS concentration. Although cytocompatibilty tests showed that inhibition of cell proliferation depended on the elution amounts of GPTMS from the pastes, an animal test using porcine tibia demonstrated no harmful systemic or local symptoms, because the GPTMS concentration maintained acceptable levels for living tissues through dispersion with body fluid. The animal test also revealed that the paste was completely resorbed and substituted with newly formed bone after 12Â weeks implantation. It was concluded based on these results that HAp/Col-GPTMS pastes are promising candidates for use as bioresorbable injectable pastes
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