Microbial activity and metamitron degrading microbial communities differ between soil and water-sediment systems.

The herbicide metamitron is frequently detected in the environment, and its degradation in soil differs from that in aquatic sediments. In this study, we applied 13C6-metamitron to investigate the differences in microbial activity, metamitron mineralization and metamitron degrading microbial communities between soil and water-sediment systems. Metamitron increased soil respiration, whereas it suppressed respiration in the water-sediment system as compared to controls. Metamitron was mineralized two-fold faster in soil than in the water-sediment. Incorporation of 13C from 13C6-metamitron into Phospholipid fatty acids (PLFAs) was higher in soil than in sediment, suggesting higher activity of metamitron-degrading microorganisms in soil. During the accelerated mineralization of metamitron, biomarkers for Gram-negative, Gram-positive bacteria and actinobacteria dominated within the 13C-PLFAs in soil. Gram-negative bacteria dominated among the metamitron degraders in sediment throughout the incubation period. Actinobacteria, and actinobacteria and fungi were the main consumers of necromass of primary degraders in soil and water-sediment, respectively. This study clearly showed that microbial groups involved in metamitron degradation depend on the system (soil vs. water-sediment) and on time. It also indicated that the turnover of organic chemicals in complex environments is driven by different groups of synthropic degraders (primary degraders and necromass degraders) rather than by a single degrader.

Liver transplantation with grafts from septuagenarians.

BACKGROUND: The purpose of this study was to evaluate our experience with orthotopic liver transplantation (OLT) using grafts from septuagenarians. PATIENTS AND METHODS: Seventeen adult patients underwent transplantation with grafts from donors 70 years of age or older during an 8-year period. RESULTS: The median donor age was 73 years (range, 70-83). Eleven (64.7%) donors had experienced at least 1 hypotensive period and received vasoactive drugs. Median cold and warm ischemia times were 7.25 hours and 35 minutes, respectively. Two recipients underwent retransplantation because of dysfunction or primary nonfunction. Morbidity rate was 47% and hospital mortality rate was 23.5%. After a median follow-up of 34.5 months (range, 3-84 months), 5 additional patients died. Median patient survival was 17 months (range, 0-84 months). One-, 3-, 5-, and 7-year cumulative survival rates were 69.7%, 57.5%, 46.2%, and 23.3%, respectively. Only graft dysfunction (P = .042) was observed to be an independent predictor of survival upon multivariate analysis. CONCLUSIONS: Although grafts from septuagenarians allow for expansion of the donor pool, long-term recipient survival is inferior to that encountered with younger donors.

Eurotransplant special request for high-urgency status after liver transplantation for hepatocellular carcinoma: a case report.

Hepatic artery thrombosis after liver transplantation remains a major indication for retransplantation. We report the case of a 49-year-old man with a hepatocellular carcinoma in the setting of cirrhosis associated with chronic hepatitis B and C infections who underwent split liver transplantation. The patient experienced a complicated postoperative course, characterized by 2 relaparotomies for necrosis of segment IV, and a late hepatic artery thrombosis, first discovered on postoperative day 20. His subsequent course was characterized by relapsing cholangitis and liver abscesses requiring antibiotics and percutaneous drainage. Transient control of the septic complications allowed for the filing of a special high-urgency status request that was approved by Eurotransplant. The patient underwent retransplantation 1 week later with a full-size deceased donor graft. He is currently alive, well, with no evidence of tumor recurrence at 30 months posttransplantation. The existence of exceptions within the system, such as the "special high-urgency status" of Eurotransplant, as well as the aggressive treatment of complications to obtain a "window of clinical opportunity" saved this patient's life.

Liver transplantation for hepatocellular carcinoma after yttrium therapy: a case report.

Yttrium-90 microspheres constitute one of the most recent treatment options for hepatocellular carcinoma (HCC) in the setting of cirrhosis. As such, their spectrum of indication is not yet fully established. Herein, we have reported the case of a patient with HCC beyond the listing criteria for liver transplantation (OLT) who was treated preoperatively with selective transarterial chemoembolization and yttrium-90 microspheres. He was subsequently transplanted with a liver from an 81-year-old donor allocated through Eurotransplant as a "rescue offer." The posttransplant course was uneventful. Pathologic examination revealed a multifocal, well-differentiated pT2 tumor with no vascular invasion. The patient is currently alive and in good condition at 14 months posttransplant, with no evidence of tumor recurrence by a current computed tomography scan. This report provided encouraging information on the potential of yttrium-90 microspheres as a bridging option before OLT for multifocal HCC.

Correction of beam errors in high power laser diode bars and stacks.

The beam errors of an 11 bar laser diode stack fitted with fast-axis collimator lenses have been corrected by a single refractive plate, produced by laser cutting and polishing. The so-called smile effect is virtually eliminated and collimator aberration greatly reduced, improving the fast-axis beam quality of each bar by a factor of up to 5. The single corrector plate for the whole stack ensures that the radiation from all the laser emitters is parallel to a common axis. Beam-pointing errors of the bars have been reduced to below 0.7 mrad.

Localized CO2 laser damage repair of fused silica optics.

A technique has been developed for the localized treatment of laser damage sites in fused silica optics by CO2 laser melt-flow smoothing, by using a 50 to 125 microm diameter beam in a regime that avoids mass removal by ablation. A detailed calibration of the laser irradiance for the threshold ablation of craters was carried out for a range of beam diameters and pulses in the 20 micros to 200 ms range. The results agree with a thermal model that also provides estimates of the melt depth for the different irradiation conditions. Smoothing trials for glass melting at irradiance values just below the ablation threshold irradiance were conducted to determine the optimum conditions and limits for the smoothing process. The technique has been found to remove damage pits up to a depth of 0.5 microm, while the small melt depth associated with localized treatment limits the smoothing to a

Low-loss passive alignment of single-mode fibers in low-temperature cofired ceramics using CO2 laser fabricated U-grooves.

We report a step toward optoelectronic integration on low-temperature cofired ceramics substrates in the form of fiber alignment U-grooves. The precision of the CO2 laser machining of green state ceramic for this purpose is investigated. The groove-writing process with a speed of 1 mm/s was carried out in air at room temperature and ambient pressure. The process is to a large extent self-cleaning without any gas jet assist. By analysis of groove profiles after firing of a near-zero shrinkage green tape formulation, it is shown that the cutting accuracy is approximately 2 microm, which is at the fundamental limit set by the particle size (1-5 microm). We demonstrate low-loss butt coupling of <1 dB for single-mode fibers using the laser written U-grooves. The technique exhibits a potential for fabrication of low-cost fiber ribbon and fiber array connectors.