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  • 2000-2004  (4)
  • 1975-1979
  • remote sensing  (2)
  • Chlorine  (1)
  • Colectomy  (1)
  • 1
    ISSN: 1530-0358
    Keywords: Colon cancer ; Surgical mortality ; Colectomy ; Veterans Affairs Medical Center ; National Surgical Quality Improvement Program
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract PURPOSE: Comorbid conditions affect the risk of adverse outcomes after surgery, but the magnitude of risk has not previously been quantified using multivariate statistical methods and prospectively collected data. Identifying factors that predict results of surgical procedures would be valuable in assessing the quality of surgical care. This study was performed to define risk factors that predict adverse events after colectomy for cancer in Department of Veterans Affairs Medical Centers. METHODS: The National Veterans Affairs Surgical Quality Improvement Program contains prospectively collected and extensively validated data on more than 415,000 surgical operations. All patients undergoing colectomy for colon cancer from 1991 to 1995 who were registered in the National Veterans Affairs Surgical Quality Improvement Program database were selected for study. Independent variables examined included 68 preoperative and 12 intraoperative clinical risk factors; dependent variables were 21 specific adverse outcomes. Stepwise logistic regression analysis was used to construct models predicting the 30-day mortality rate and 30-day morbidity rates for each of the ten most frequent complications. RESULTS: A total of 5,853 patients were identified; 4,711 (80 percent) underwent resection and primary anastomosis. One or more complications were observed in 1,639 of 5,853 (28 percent) patients. Prolonged ileus (439/5,853; 7.5 percent), pneumonia (364/5,853; 6.2 percent), failure to wean from the ventilator (334/5,853; 5.7 percent), and urinary tract infection (292/5,853; 5 percent) were the most frequent complications. The 30-day mortality rate was 5.7 percent (335/5,853). For most complications, 30-day in-hospital mortality rates were significantly higher for patients with a complication than for those without. Thirty-day mortality rates exceeded 50 percent if postoperative coma, cardiac arrest, a pre-existing vascular graft prosthesis that failed after colectomy, renal failure, pulmonary embolism, or progressive renal insufficiency occurred. Preoperative factors that predicted a high risk of 30-day mortality included ascites, serum sodium 〉145 mg/dl, “do not resuscitate” status before surgery, American Society of Anesthesiologists classes III and IV OR V, and low serum albumin. CONCLUSIONS: Mortality rates after colectomy in Veterans Affairs hospitals are comparable with those reported in other large studies. Ascites, hypernatremia, do not resuscitate status before surgery, and American Society of Anesthesiologists classes III and IV OR V were strongly predictive of perioperative death. Clinical trials to decrease the complication rate after colectomy for colon cancer should focus on these risk factors.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of material cycles and waste management 2 (2000), S. 89-99 
    ISSN: 1611-8227
    Keywords: Key words Waste combustion ; Bromine ; Chlorine ; Flame-retarded plastics ; Metal volatilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Co-combustion tests of municipal solid waste and bromine-containing waste plastics have been performed in the TAMARA test incinerator in order to investigate the fate of bromine in waste combustion. HBr is the main bromine combustion product. Approximately 50% of the bromine inventory stays in the grate ashes, which is much more than is found for chlorine. The percentage of bromine transferred into the fly ash also exceeds that of chlorine. There is a strong indication that bromine has a promoting effect upon the volatility of most of the heavy metals that are typically mobilized by chlorine.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1573-5079
    Keywords: chlorophyll ; energy quenching ; fluorescence ; LIDAR ; photochemistry ; photosynthesis ; Photosystem II ; phytoplankton ; pump and probe ; remote sensing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Initial results of the airborne LIDAR measurement of photochemical quantum yield, ΦPo, and functional absorption cross-section, σPS II, of Photosystem II (PS II) are reported. NASA's AOL3 LIDAR was modified to implement short-pulse pump-and-probe (SP-P&P) LIDAR measurement protocol. The prototype system is capable of measuring a pump-induced increase in probe-stimulated chlorophyll fluorescence, ΔF/Fsat, along with the acquisition of `conventional' LIDAR-fluorosensor products from an operational altitude of 150 m. The use of a PS II sub-saturating probe pulse increases the response signal but also results in excessive energy quenching (EEQ) affecting the ΔF/Fsat magnitude. The airborne data indicated up to a 3-fold EEQ-caused decline in ΔF/Fsat, and 2-fold variability in the EEQ rate constant over a spatial scale a few hundred kilometers. Therefore, continuous monitoring of EEQ parameters must be incorporated in the operational SP-P&P protocol to provide data correction for the EEQ effect. Simultaneous airborne LIDAR measurements of ΦPo and σPS II with EEQ correction were shown to be feasible and optimal laser excitation parameters were determined. Strong daytime ΔF/Fsat decline under ambient light was found in the near-surface water layer over large aquatic areas. An example of SP-P&P LIDAR measurement of phytoplankton photochemical and fluorescent characteristics in the Chesapeake Bay mouth is presented. Prospects for future SP-P&P development and related problems are discussed.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1573-5079
    Keywords: chlorophyll ; fluorescence ; LIDAR ; photosynthesis ; Photosystem II ; pump and probe ; remote sensing ; singlet-singlet quenching ; singlet-triplet quenching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The development of a technique for laser measurement of fPhotosystem II (PS II) photochemical characteristics of phytoplankton and terrestrial vegetation from an airborne platform is described. Results of theoretical analysis and experimental study of pump-and-probe measurement of the PS II functional absorption cross-section and photochemical quantum yield are presented. The use of 10 ns probe pulses of PS II sub-saturating intensity provides a significant, up to 150-fold, increase in the fluorescence signal compared to conventional `weak-probe' protocol. Little effect on the fluorescence yield from the probe-induced closure of PS II reaction centers is expected over the short pulse duration, and thus a relatively intense probe pulse can be used. On the other hand, a correction must be made for the probe-induced carotenoid triplet quenching and singlet-singlet annihilation. A Stern-Volmer model developed for this correction assumes a linear dependence of the quenching rate on the laser pulse fluence, which was experimentally validated. The PS II saturating pump pulse fluence (532 nm excitation) was found to be 10 and 40 μmol quanta m−2 for phytoplankton samples and leaves of higher plants, respectively. Thirty μs was determined as the optimal delay in the pump-probe pair. Our results indicate that the short-pulse pump-and-probe measurement of PS II photochemical characteristics can be implemented from an airborne platform using existing laser and LIDAR technologies.
    Type of Medium: Electronic Resource
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