Harmonization of VFAs measurement by GC: something more than R2 to evaluate the calibration function

Anaerobic digestion is sensitive to many environmental factors requiring a robust control of this process. One of the analytical measurements considered as key parameter is the volatile fatty acids (VFAs) content. Total amount of volatile acids (TVFA) to control the relative changes over time has been suggested as a useful tool. However, TVFA does not provide sufficient information to reveal the overall reactor performance, and individual components have been considered of particular interest. Although some attempts have been described as on-line measurements for individual VFAs, normally they are determined by off-line chromatographic techniques (GC and HPLC). A previous interlaboratory study showed the lack of harmonization in the analytical methodologies dealing to individual VFAs, and giving an overall analytical performance rather poor. One of the reasons to justify these results was the inappropriate calibration procedures. It is widely used to check the linearity of the calibration curves based on the correlation and determination coefficients. However, these statistical parameters are erroneously interpreted. The objective of this interlaboratory study was to achieve the harmonization of results. By this way, the use of internal standard methodology (ISTD) should be useful to obtain accurate calibration functions. In addition, five different statistical parameters such as lack of fit test, residual standard deviation, relative standard deviation of the slope, relative standard deviation of the sensitivity and relative error were proposed to evaluate the linearity of calibration curves. Of these, lack of fit was unable to detect appropriately the linearity mainly due to its sensitivity to the precision of analytical results. The rest of statistical parameters reported could be considered as starting point for comparative purposes, being useful as acceptance criteria. The principal advantage of the GC/ISTD analytical methodology was the normalization of the slopes obtained by the participating laboratories, being very helpful to the harmonization of results.Peer Reviewe

A multicentre outcome analysis to define global benchmarks for donation after circulatory death liver transplantation

BACKGROUND: To identify the best possible outcomes in liver transplantation from donation after circulatory death donors (DCD) and to propose outcome values, which serve as reference for individual liver recipients or patient groups. METHODS: Based on 2219 controlled DCD liver transplantations, collected from 17 centres in North America and Europe, we identified 1012 low-risk, primary, adult liver transplantations with a laboratory MELD of ≤20points, receiving a DCD liver with a total donor warm ischemia time of ≤30minutes and asystolic donor warm ischemia time of ≤15minutes. Clinically relevant outcomes were selected and complications were reported according to the Clavien-Dindo-Grading and the Comprehensive Complication Index (CCI). Corresponding benchmark cut-offs were based on median values of each centre, where the 75(th)-percentile was considered. RESULTS: Benchmark cases represented between 19.7% and 75% of DCD transplantations in participating centers. The one-year retransplant and mortality rate was 5.23% and 9.01%, respectively. Within the first year of follow-up, 51.1% of recipients developed at least one major complication (≥Clavien-Dindo-Grade-III). Benchmark cut-offs were ≤3days and ≤16days for ICU and hospital stay, ≤66% for severe recipient complications (≥Grade-III), ≤16.8% for ischemic cholangiopathy, and ≤38.9CCI points at one-year posttransplant. Comparisons with higher risk groups showed more complications and impaired graft survival, outside the benchmark cut-offs. Organ perfusion techniques reduced the complications to values below benchmark cut-offs, despite higher graft risk. CONCLUSIONS: Despite excellent 1-year survival, morbidity in benchmark cases remains high with more than half of recipients developing severe complications during 1-year follow-up. Benchmark cut-offs targeting morbidity parameters offer a valid tool to assess the protective value of new preservation technologies in higher risk groups, and provide a valid comparator cohort for future clinical trials. LAY SUMMARY: The best possible outcomes after liver transplantation of grafts donated after circulatory death (DCD) were defined using the concept of benchmarking. These were based on 2219 liver transplantations following controlled DCD donation in 17 centres worldwide. The following benchmark cut-offs for the most relevant outcome parameters were developed: ICU and hospital stay: ≤3 and ≤16 days; primary non function: ≤2.5%; renal replacement therapy: ≤9.6%; ischemic cholangiopathy: ≤16.8% and anastomotic strictures ≤28.4%. One-year graft loss and mortality were defined as ≤14.4% and 9.6%, respectively. Donor and recipient combinations with higher risk had significantly worse outcomes. The use of novel organ perfusion technology achieved similar, good results in this high-risk group with prolonged donor warm ischemia time, when compared to the benchmark cohort

A multicentre outcome analysis to define global benchmarks for donation after circulatory death liver transplantation

Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Laparoscopic Living-Donor Nephrectomy of a Horseshoe Kidney: A Case Report and Review of the Literature

We present the case of a living-donor nephrectomy of a horseshoe kidney. The recipient was a 33-year-old male with a history of end-stage renal disease secondary to IgA nephropathy. The donor was his 33-year-old partner who on preoperative cross-sectional imaging was found to have a horseshoe kidney with a single artery, vein and ureter. The donor operation was performed using a laparoscopic hand-assisted technique with transection of the interpolar fibrotic band using a stapler device. The backtable organ preparation was performed in a standard fashion with addition of a reinforcing hemostatic suture of the stapled fibrotic band. The donated kidney was transplanted extraperitoneally in the right iliac fossa of the recipient. The patient had an unremarkable postoperative course and was discharged home on post operative day 2 with normalizing renal function. To our knowledge, this is the first living donor nephrectomy of a horseshoe kidney performed using a laparoscopic hand-assisted technique

Laparoscopic Living-Donor Nephrectomy of a Horseshoe Kidney: A Case Report and Review of the Literature

We present the case of a living-donor nephrectomy of a horseshoe kidney. The recipient was a 33-year-old male with a history of end-stage renal disease secondary to IgA nephropathy. The donor was his 33-year-old partner who on preoperative cross-sectional imaging was found to have a horseshoe kidney with a single artery, vein and ureter. The donor operation was performed using a laparoscopic hand-assisted technique with transection of the interpolar fibrotic band using a stapler device. The backtable organ preparation was performed in a standard fashion with addition of a reinforcing hemostatic suture of the stapled fibrotic band. The donated kidney was transplanted extraperitoneally in the right iliac fossa of the recipient. The patient had an unremarkable postoperative course and was discharged home on post operative day 2 with normalizing renal function. To our knowledge, this is the first living donor nephrectomy of a horseshoe kidney performed using a laparoscopic hand-assisted technique

Synthesis of Gold Nanoparticles from Gold Coatings Recovered from E-Waste Processors

This work presents the synthesis of Au nanoparticles from gold coatings recovered from processor pins with minimal waste generation. The process consisted of four main steps: (1) physical recovery of pins, (2) recovery of gold coatings by acid digestion, (3) synthesis of HAuCl4 under mild conditions and, (4) synthesis of Au nanoparticles by the Turkevich method. The small dimensions of Au coatings allowed the synthesis of HAuCl4 with lower amounts of HClconc and HNO3conc than those used with aqua regia. This method has significant advantages, such as lower NO2(g) emission, easy post-treatment and purification, low synthesis cost and high yields. Gold nanoparticles synthesized from HAuCl4 were characterized by transmission electron microscopy (TEM) and UV-Vis spectroscopy. Size distribution analysis showed particles 14.23 nm in length and 12.05 nm in width, while absorption spectra showed a surface plasmon located at 523 nm; these characteristics were very similar to those observed with Au nanoparticles obtained with Aldrich’s reagent. It is suggested that recycling procedures can be improved by taking into account the size and shape of the metals to be recovered, thus introducing a new field of research known as hydronanometallurgy