Bioenergy is one of the main contributors in the renewable energy markets but the quality of solid biomass is often a concern. This study provides an application of the ISO 18135 on biomass sampling, ...evaluating how sampling procedure affects the analytical results and suggesting possible solutions to reach an acceptable level of precision for quality assessment.
A sampling plan compliant with the aforementioned standard was carried out in a 21 MW biomass power plant located in Northern Italy in August and February, collecting samples of different typology from heaps stored in the plant and from trucks coming from suppliers. Moisture content analysis was performed for all the samples, and for those from heaps ash and nitrogen contents were also investigated.
Considering moisture content, to achieve a good precision, a significantly different number of increments are needed in August and February. Regarding ash content, it would be impossible to obtain the precision suggested by the standard, because it would lead to a number of increments not in line with practical operations. Nitrogen content is not a concern in this case, because of the measured low values. In general terms, precision values suggested by ISO 18135 require a high effort by operator and resulted unsuitable in terms of practical application for moisture and ash contents. This is probably due to the different solid biomass considered during the standard development.
For this reason, it is important to assess the quality of the different solid biofuels in order to tune the sampling procedure accordingly.
Considering the ambitious European targets for reducing greenhouse gas emissions the energy production from renewable energy sources is increasing as well as the number of biomass power plants. ...Biomass is a valid alternative to fossil fuels because it is present worldwide and in different forms. Of course, it is important to assess its quality not only for energy characteristics but also for environmental and operational aspects. In this study more than 1700 woodchip samples have been collected in several Italian power plants and the most important physical and chemical parameters have been analyzed to investigate their quality. These data have been compared with the specification expressed in the recently published ISO/TS 17225-9 technical standard. The results show that the ash content is a fundamental and representative parameter for assessing the biofuel quality and that a certain amount of samples has low quality mainly because of their high ash content. In addition, ANOVA results demonstrated that the quality classes expressed in the standard up to 7% ash content are essential in order to meet the needs of the Italian woodchip market. Beyond the value of 7% in ash content, chlorine, sulfur and nitrogen contents increase significantly with consequences for technical and environmental aspects.
Pretransplant donor biopsy (PTDB)‐based marginal donor allocation systems to single or dual renal transplantation could increase the use of organs with Kidney Donor Profile Index (KDPI) in the ...highest range (e.g. >80 or >90), whose discard rate approximates 50% in the United States. To test this hypothesis, we retrospectively calculated the KDPI and analyzed the outcomes of 442 marginal kidney transplants (340 single transplants: 278 with a PTDB Remuzzi score <4 median KDPI: 87; interquartile range (IQR): 78–94 and 62 with a score = 4 median KDPI: 87; IQR: 76–93; 102 dual transplants median KDPI: 93; IQR: 86–96) and 248 single standard transplant controls (median KDPI: 36; IQR: 18–51). PTDB‐based allocation of marginal grafts led to a limited discard rate of 15% for kidneys with KDPI of 80–90 and of 37% for kidneys with a KDPI of 91–100. Although 1‐year estimated GFRs were significantly lower in recipients of marginal kidneys (−9.3, −17.9 and −18.8 mL/min, for dual transplants, single kidneys with PTDB score <4 and =4, respectively; p < 0.001), graft survival (median follow‐up 3.3 years) was similar between marginal and standard kidney transplants (hazard ratio: 1.20 95% confidence interval: 0.80–1.79; p = 0.38). In conclusion, PTDB‐based allocation allows the safe transplantation of kidneys with KDPI in the highest range that may otherwise be discarded.
This study shows that the standardized assessment of formalin‐fixed pretransplant biopsies helps recover donors with KDPI in the highest range that would be otherwise discarded, and by providing the expected graft outcomes based on KDPI and pretransplant biopsy, it guides the clinician facing the difficult decision whether to accept or reject these organs. See editorial by Gupta et al on page 2444.
Although split regimen is associated with higher adenoma detection and is recommended for elective colonoscopy, its adoption remains suboptimal. The identification of patient-related barriers may ...improve its implementation. Our aim was to assess patients' attitude towards split regimen and patient-related factors associated with its uptake.
In a multicentre, prospective study, outpatients undergoing colonoscopy from 8:00 to 14:00 were given written instructions for 4 L polyethylene glycol bowel preparation, offering the choice between split-dose and day-before regimens and emphasising the superiority of split regimen on colonoscopy outcomes. Uptake of split regimen and association with patient-related factors were explored by a 20-item questionnaire.
Of the 1447 patients (mean age 59.2±13.5 years, men 54.3%), 61.7% and 38.3% chose a split-dose and day-before regimens, respectively. A linear correlation was observed between time of colonoscopy appointments and split-dose uptake, from 27.3% in 8:00 patients to 96% in 14:00 patients (p<0.001, χ
for linear trend). At multivariate analysis, colonoscopy appointment before 10:00 (OR 0.14, 95% CI 0.11 to 0.18), travel time to endoscopy service >1 h (OR 0.55, 95% CI 0.38 to 0.79), low education level (OR 0.72, 95% CI 0.54 to 0.96) and female gender (OR 0.74, 95% CI 0.58 to 0.95) were inversely correlated with the uptake of split-dose. Overall, the risk of travel interruption and faecal incontinence was slightly increased in split regimen patients (3.0% vs 1.4% and 1.5% vs 0.9%, respectively; p=NS). Split regimen was an independent predictor of adequate colon cleansing (OR 3.34, 95% CI 2.40 to 4.63) and polyp detection (OR 1.46, 95% CI 1.11 to 1.92).
Patient attitude towards split regimen is suboptimal, especially for early morning examinations. Interventions to improve patient compliance (ie, policies to reorganise colonoscopy timetable, educational initiatives for patient and healthcare providers) should be considered.
NCT02287051; pre-result.
Abstract One of the main problems in transplant surgery is the preservation of the organ during the cold ischemic time. The interrupted blood supply triggers a cascade of biological modifications ...resulting in cell death, which predisposes to discharge of a large quantity of toxic metabolites at the moment of organ reperfusion. Many approaches have been studied to prevent the toxic processes. Immediately after procurement, kidneys are flushed with these solutions. Two main: techniques of organ preservation are cold static storage and hypothermic machine perfusion (HMP). Based on age and comorbidities, individuals can be generally divided into 2 groups: ideal and marginal donors. Characteristics of organs from marginal donors are associated with an increased rate of delayed graft function and primary graft nonfunction (PNF), which reduce transplant survival and increase the acute rejection risk. In the last 20 years, the United Network of Organ Sharing has reported a 170% increase in deceased donors older than 50 years of age. Techniques of perfusion have been demonstrated to play a pivotal role in graft function after transplantation. Some studies suggest that HMP may improve outcomes after transplantation.
Abstract Background Kidney transplant recipients (KTRs) manifest hypercoagulable state that contributes to an increased incidence of deep vein thrombosis (DVT), not only early but also late in their ...course. KTRs display an imbalance of hemostatic mechanisms with a multifactorial rise in procoagulant factors, partly related to traditional risk factors and partly to transplantation. The aim of this study was to evaluate the incidence of first episodes of DVT among KTRs, focusing on risk factors. Methods From 2008 to 2011, we evaluated 30 kidney transplant patients who ≥4 months there after transplantation developed DVT in the lower limbs only, lower limbs complicated by pulmonary embolism or retinal thrombosis. We analyzed causes of primary nephropathy, immunosuppressive regimen, post-transplantation infections, and erythrocytosis. DVT was diagnosed by color Doppler ultrasound or eye examination. Results A significantly increased incidence of DVT was observed among patients receiving cyclosporine or cyclosporine + mammalian target of rapamycin inhibitors, affected by polycystic kidney diseases, systemic lupus erythematosus or nephrotic syndrome, or displaying rapid and/or excessive correction of hematocrit values. DVT was not significantly related to an acute infection (cytomegalovirus) or to the prior dialysis modality. Conclusions Hypercoagulability is a multifactorial condition in KTRs, representing a severe complication in stable patients. Prevention may consist of either accurate pretransplantation screening for thrombophilia or identification of patients at higher DVT risk.
Abstract We analyzed the results of kidney transplantation in autosomal dominent polycystic kidney disease (ADPKD) patients in Italy, including 14,305 transplantations performed from January 2002 to ...December 2010, including: 12,859 first single or double kidneys from cadaveric donors (13% polycystic), 172 combined liver-kidney cases (22% polycystic), and 1,303 living-donor organs (7% polycystic). Among the first transplantations (12,008 single, 851 double), with follow-ups ranging from 16 to 120 months, polycystic patients demonstrated better graft survival compared with other kidney diseases (86% vs 82% at 5 years; P < .01); mortality was not different (92% vs 79% at 1 year). A better trend was obtained also among combined liver-kidney transplantations in ADPKD. Regarding pretransplantation management of polycystic patients, we noticed a conservative attitude in 32/35 transplant centers. The main indication for nephrectomy was for the lack of abdominal space. Regarding instrumental studies, 86% of centers asked for second-level investigations computerized tomography for kidney dimensions. Radiologic investigations for vasculocerebral malformations were required in 97% of the centers: 74% as a routine and 23% in the presence of familial history of cerebral hemorrhage. Polycystic patients are good candidates for kidney transplantation with correct management before transplantation.
Abstract Background Combined liver-kidney transplantation (LKT) is considered to be a safe procedure, but the appropriate immunosuppressive regimen is unclear. Patients and methods Between January ...1997 and October 2011, 55 patients were listed for LKT: 45 (82%) were effectively transplanted, 5 (9.2%) died whereon here the waiting list, 3 (5.5%) temporarily out of waiting list, 1 (1.8%) was on waiting list and 1 (1.8%) refused LKT. Five LKTs treated with cyclosporine (CyA) were excluded from the analysis. Mean recipient age was 50.32 ± 10.32 years (14–65), MELD score at time of LKT was 19.22 ± 4.69 (8–29), mean waiting list time was 8.14 ± 9.50 months (0.1–35.76), and follow-up, 4.09 ± 3.02 years (0.01–10.41). Main indications for LKT were policystic disease (n = 15; 37%), hepatitis virus C (HCV)-related cirrhosis (n = 9; 22%) metabolic disease (n = 5; 13%), hepatitis virus B (HBV) cirrhosis (n = 4; 10%), alcoholic cirrhosis (n = 4; 10%), and cholestatic disease (n = 3; 8%). Immunosuppressive regimen was based on tacrolimus and steroids in 40 cases with induction therapy with alemtuzumab (Campath; 0.3 mg/kg) in 13 of 40 instances cases administered on day 0 and day 7. Results Postoperative mortality was 2.5%. Acute cellular rejection episodes were biopsy-proven in 2 (5%) cases, post-LKT infections developed in 17 cases (42.5%), and de novo cancer developed in 3 (7.5%) cases. Similar 5-year overall survivals were obtained irrespective of the LKT indication: 100% in cholestatic and alcoholic cirrhosis patients, 86% in policystic disease, 75% in metabolic disease and HBV patients, and 66% in HCV cirrhosis. Overall survivals for the alemtuzumab vs without-induction therapy groups at 1, 3, and 5-years were 100%, 85.7%, and 85.7% vs 76%, 76%, and 70%, respectively ( P = .04). Conclusion An immunosuppressive regimen based on tacrolimus and steroids with induction therapy with alemtuzumab was safe, with excellent long-term results for combined LKT.
Purpose
β2-microglobulin amyloidosis (Aβ
2
M) is one of the main long-term complications of dialysis treatment. The incidence and the onset of Aβ
2
M has been related to membrane composition and/or ...dialysis technique, with non-homogeneous results. This study was carried out to detect: i) the incidence of bone cysts and CTS from Aβ
2
M; ii) the difference in Aβ
2
M onset between cellulosic and synthetic membranes; iii) other risk factors besides the membrane.
Methods
480 HD patients were selected between 1986 to 2005 and grouped according to the 4 types of membranes used (cellulose, synthetically modified cellulose, synthetic low-flux, synthetic high-flux). The patients were analyzed before and after 1995, when the reverse osmosis treatment for dialysis water was started at our center, and the incidence of Aβ
2
M was compared between the two periods. Routine plain radiography, computer tomography (CT) and nuclear magnetic resonance imaging (MRI) as well as electromyography were used to investigate the clinical symptoms.
Results
Bone cysts occurred in 29.2% of patients before 1995 vs. 12.2% after 1995 (p<0.0001). CTS occurred in 24% of patients before 1995 vs. 7.1% after 1995 (p<0.0001). Bone cysts and CTS occurred in older patients, who began dialysis at a late age, with high CRP, low albumin, low residual GFR, and low Hb. Cox regression analysis showed that the risk factor for bone cysts was high CRP (RR 1.3, p<0.01), while albumin (RR 0.14, p<0.0001) and residual GFR (RR 0.81, p<0.0001) were revealed to be protective factors. Cox analysis for CTS confirmed CRP as a risk factor (RR 1.2, p<0.01), and albumin (RR 0.59, p<0.0001) and residual GFR (RR 0.75, p<0.0001) as protective factors. The comparison obtained between membranes did not suggest any protective effect on Aβ
2
M.
Conclusions
The findings that the inflammatory status as well as low albumin and the residual GFR of the uremic patient are predictive of Aβ
2
M lesions suggests that Aβ
2
M has a multifactorial origin rather than being solely a membrane- or technique-related side effect.
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