22 research outputs found
Analysis of hydration and subchondral bone density on the viscoelastic properties of bovine articular cartilage.
Funding JC is currently funded by an Engineering and Physical Sciences Research Council scholarship (EP/N509590/1). We are also grateful to Arthritis Research UK for the award of a PhD studentship to Anna A. Cederlund (Grant number 19971). The materials and testing equipment used in this study was funded by an Arthritis Research UK grant (H0671). The Engineering and Physical Sciences Research Council and Arthritis Research UK (now part of Versus Arthritis) had no role in the design of the study and collection, analysis and interpretation of data and in writing the manuscript.Peer reviewedPublisher PD
Robot-Assisted Total Mesorectal Excision Versus Laparoscopic Total Mesorectal Excision:A Retrospective Propensity Score-Matched Cohort Analysis in Experienced Centers
BACKGROUND: The superiority of robot-assisted over laparoscopic total mesorectal excision has not been proven. Most studies do not consider the learning curve while comparing the surgical technique. OBJECTIVE: This study aims to compare laparoscopic with robot-assisted total mesorectal excision performed by surgeons who completed the learning curve of the technique. DESIGN: This is a multicenter retrospective propensity score-matched analysis. SETTINGS: The study was performed in 2 large, dedicated robot-assisted hospitals and 5 large, dedicated laparoscopic hospitals. PATIENTS: Patients were included if they underwent a robot-assisted or laparoscopic total mesorectal excision for rectal cancer with curative intent at a dedicated center for the minimally invasive technique between January 1, 2015, and December 31, 2017. INTERVENTIONS: We compared robot-assisted with laparoscopic total mesorectal excision. MAIN OUTCOME MEASURES: The main outcome was conversion to laparotomy during surgery. Secondary outcomes were postoperative morbidity and positive circumferential resection margin. RESULTS: A total of 884 patients were included and, after matching, 315 patients per treatment group remained. Conversion was similar between laparoscopic and robot-assisted total mesorectal excision (4.4% vs 2.5% (p = 0.20)). Positive circumferential resection margin was equal (3.2% vs 4.4% (p = 0.41)). Overall morbidity was comparable as well, although a lower rate of wound infections was observed in the robot-assisted group (5.7% vs 1.9% (p = 0.01)). More primary anastomoses were constructed in the robot-assisted group (50.8% vs 68.3% (p < 0.001)). Finally, more open procedures were performed in dedicated laparoscopic centers, with an overrepresentation of cT4N+ tumors in this group. LIMITATIONS: This is a retrospective multicenter cohort; however, propensity score matching was applied to control for confounding by indication. CONCLUSIONS: Robot-assisted and laparoscopic total mesorectal excision are equally safe in terms of short-term outcomes. However, with the robot-assisted approach, more primary anastomoses were constructed, and a lower wound infection rate was observed. See Video Abstract at http://links.lww.com/DCR/B677
Laparoscopic ileocolic resection versus infliximab treatment of distal ileitis in Crohn's disease: a randomized multicenter trial (LIR!C-trial)
Contains fulltext :
69534.pdf (publisher's version ) (Open Access)BACKGROUND: With the availability of infliximab, nowadays recurrent Crohn's disease, defined as disease refractory to immunomodulatory agents that has been treated with steroids, is generally treated with infliximab. Infliximab is an effective but expensive treatment and once started it is unclear when therapy can be discontinued. Surgical resection has been the golden standard in recurrent Crohn's disease. Laparoscopic ileocolic resection proved to be safe and is characterized by a quick symptom reduction.The objective of this study is to compare infliximab treatment with laparoscopic ileocolic resection in patients with recurrent Crohn's disease of the distal ileum with respect to quality of life and costs. METHODS/DESIGN: The study is designed as a multicenter randomized clinical trial including patients with Crohn's disease located in the terminal ileum that require infliximab treatment following recent consensus statements on inflammatory bowel disease treatment: moderate to severe disease activity in patients that fail to respond to steroid therapy or immunomodulatory therapy. Patients will be randomized to receive either infliximab or undergo a laparoscopic ileocolic resection. Primary outcomes are quality of life and costs. Secondary outcomes are hospital stay, early and late morbidity, sick leave and surgical recurrence. In order to detect an effect size of 0.5 on the Inflammatory Bowel Disease Questionnaire at a 5% two sided significance level with a power of 80%, a sample size of 65 patients per treatment group can be calculated. An economic evaluation will be performed by assessing the marginal direct medical, non-medical and time costs and the costs per Quality Adjusted Life Year (QALY) will be calculated. For both treatment strategies a cost-utility ratio will be calculated. Patients will be included from December 2007. DISCUSSION: The LIR!C-trial is a randomized multicenter trial that will provide evidence whether infliximab treatment or surgery is the best treatment for recurrent distal ileitis in Crohn's disease. TRIAL REGISTRATION: Nederlands Trial Register NTR1150
The ladies trial: laparoscopic peritoneal lavage or resection for purulent peritonitisA and Hartmann's procedure or resection with primary anastomosis for purulent or faecal peritonitisB in perforated diverticulitis (NTR2037)
Background: Recently, excellent results are reported on laparoscopic lavage in patients with purulent perforated diverticulitis as an alternative for sigmoidectomy and ostomy. The objective of this study is to determine whether LaparOscopic LAvage and drainage is a safe and effective treatment for patients with purulent peritonitis (LOLA-arm) and to determine the optimal resectional strategy in patients with a purulent or faecal peritonitis (DIVA-arm: perforated DIVerticulitis: sigmoidresection with or without Anastomosis). Methods/Design: In this multicentre randomised trial all patients with perforated diverticulitis are included. Upon laparoscopy, patients with purulent peritonitis are treated with laparoscopic lavage and drainage, Hartmann's procedure or sigmoidectomy with primary anastomosis in a ratio of 2:1:1 (LOLA-arm). Patients with faecal peritonitis will be randomised 1:1 between Hartmann's procedure and resection with primary anastomosis (DIVA-arm). The primary combined endpoint of the LOLA-arm is major morbidity and mortality. A sample size of 132:66:66 patients will be able to detect a difference in the primary endpoint from 25% in resectional groups compared to 10% in the laparoscopic lavage group (two sided alpha = 5%, power = 90%). Endpoint of the DIVA-arm is stoma free survival one year after initial surgery. In this arm 212 patients are needed to significantly demonstrate a difference of 30% (log rank test two sided alpha = 5% and powe
Performance of a Constructed Wetland and Pretreatment System Receiving Potato Farm Wash Water
Many potato processors require on-farm washing of potatoes, creating large quantities of wastewater that requires treatment, starting in the fall until the end of the potato storage period in mid-summer. We studied the treatment of wastewater from a potato farm in Ontario, Canada, using a system of pretreatment (sedimentation, aeration) followed by a surface-flow wetland with a dense growth of cattails (Typha sp.). The raw wastewater had high average concentrations of 5-day biochemical oxygen demand (BOD5; 1113 mg·L−1), total suspended solids (TSS; 4338 mg·L−1), total nitrogen (TN; 311 mg·L−1) and total phosphorus (TP; 42.5 mg·L−1). Due to high influent loads, the pretreatment was enlarged during annual sediment cleaning at the end of Year 1 (Y1), which increased the hydraulic retention time and delayed the seasonal onset of wetland loading from winter in Y1 to spring in Year 2 (Y2). Total concentration reduction for the treatment system (pretreatment + wetland) in Y2 was 96% BOD5, 99% TSS, 86% TN and 90% TP; and in Y1 was 79% BOD5, 97% TSS, 62% TN and 54% TP. Overall, the best treatment in both the pretreatment and the wetland was seen in spring months. The enlarged pretreatment system enabled seasonal loading of the wetland during the spring and summer, which facilitated improved treatment performance
The effectiveness of Hemopatch™ in preventing postoperative distal pancreatectomy fistulas
Post-operative fistula after distal pancreatectomy (DP) is still a significant complication, although many tools and tips have been utilized to try to reduce its elevated frequency. This paper focuses on the role of a sealing hemostatic device, Hemopatch™, to prevent postoperative pancreatic fistula (POPF) after DP
Impact of manure storage conditions and time on decomposition and losses from liquid dairy manure stored in a temperate climate
Large volumes of generated animal manures necessitate knowledge of how its production and storage affects composition, losses, and utilization potential. Stratification of liquid dairy manure was the main source of observed variability within outdoor uncovered manure storage, during a yearlong monitoring of 24 different physicochemical manure parameters. Coefficient of variation (CV) ranged from 4-24% for plant nutrients to 33-89% for biogas feedstock parameters. N volatilization losses during storage between manure additions were ~10% moThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Impact of manure storage conditions and time on decomposition and losses from liquid dairy manure stored in a temperate climate
Large volumes of generated animal manures necessitate knowledge of how its production and storage affects composition, losses, and utilization potential. Stratification of liquid dairy manure was the main source of observed variability within outdoor uncovered manure storage, during a yearlong monitoring of 24 different physicochemical manure parameters. Coefficient of variation (CV) ranged from 4-24% for plant nutrients to 33-89% for biogas feedstock parameters. N volatilization losses during storage between manure additions were ~10% moThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Characterizing the Performance of Gas-Permeable Membranes as an Ammonia Recovery Strategy from Anaerobically Digested Dairy Manure
Capturing ammonia from anaerobically digested manure could simultaneously decrease the adverse effects of ammonia inhibition on biogas production, reduce reactive nitrogen (N) loss to the environment, and produce mineral N fertilizer as a by-product. In this study, gas permeable membranes (GPM) were used to capture ammonia from dairy manure and digestate by the diffusion of gaseous ammonia across the membrane where ammonia is captured by diluted acid, forming an aqueous ammonium salt. A lab-scale prototype using tubular expanded polytetrafluoroethylene (ePTFE) GPM was used to (1) characterize the effect of total ammonium nitrogen (TAN) concentration, temperature, and pH on the ammonia capture rate using GPM, and (2) to evaluate the performance of a GPM system in conditions similar to a mesophilic anaerobic digester. The GPM captured ammonia at a rate between 2.2 to 6.3% of gaseous ammonia in the donor solution per day. Capture rate was faster in anaerobic digestate than raw manure. The ammonia capture rate could be predicted using non-linear regression based on the factors of total ammonium nitrogen concentration, temperature, and pH. This use of membranes shows promise in reducing the deleterious impacts of ammonia on both the efficiency of biogas production and the release of reactive N to the environment
INTEGRATING WATERSHED AND ECOSYSTEM SERVICE MODELS TO ASSESS BEST MANAGEMENT PRACTICE EFFICIENCY: GUIDELINES FOR LAKE ERIE MANAGERS AND WATERSHED MODELLERS
Lake Erie is the shallowest and most biologically productive system of the Great Lakes, surrounded by large urban, industrial and agricultural areas. This combination prompted extensive efforts to promote Best Management Practices (BMPs) to mitigate non-point source pollution in Lake Erie’s watershed. Recent technical and conceptual advancements caution that significant variability exists in the BMP efficiency to reduce the severity of runoff and nutrient concentrations due to differences in implementation, the dependence of operational performance on local soil and climatic conditions, storm events and seasonality, and declining performance over time owing to imperfect maintenance. Given the uncertainty surrounding the design and efficiency of BMPs in abating non-point source pollution, our primary objective is to review the critical strengths and potential weaknesses of nine agricultural BMPs promoted for use in the Lake Erie watershed. We examine the capacity of the current generation of watershed process-based models to recreate possible BMP-mediated changes in the water and nutrient cycles. After reviewing modelling strategies (dynamic, external forcing, and empirical) to recreate non-linear watershed responses and feedback loops to BMP efficiency, our study recommends adopting dynamic representations of the interplay among key mechanisms, like soil moisture, water table, nutrient availability, plant uptake and subsequent growth. Notwithstanding the increased sophistication of complex mathematical models, their learning capacity is usually compromised by the coarse resolution of environmental data and limited empirical knowledge to accurately parameterize environmental properties and partially understood biogeochemical processes. In this context, we highlight the expression of the value of ecosystem services in monetary terms as a critical information piece when considering trade-offs among costly and diverse policy decisions. Consistent with the Integrated Watershed Management framework, we advocate the adoption of a rigorous mass-balance approach to assess the impact of BMPs on nutrient cycles, as well as the integration of the projected environmental improvements with terrestrial ecosystem services, beneficial use impairments, and aquatic ecosystem services. The proposed strategy has the potential to improve the decision-making process by identifying cost-effective management actions and balancing different goods and services provided by the agroecosystems at different time scales.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author