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Due to the projected decline of demand for gasoline in light duty engines and the advent of ethanol as a green fuel, the use of gasoline/ethanol blend fuels in heavy duty applications are being investigated as they are projected to have lower cost and lower lifecycle green house gas (GHG) emissions. In heavy duty engines, the primary mode of combustion is mixing controlled combustion where wide range of mixture conditions (equivalence ratio) exist. Soot emissions of these fuels in richer conditions are not well understood. The goal of this research is to evaluate some commercially available soot modeling codes for the particulate matter emissions from gasoline/ethanol fuel blends, especially at fuel rich conditions. A Rapid Compression Machine (RCM) is modeled in a three-dimensional numerical simulation using CONVERGE computational software using a reduced chemical kinetic mechanism with SAGE chemistry solver and a RANS k-ϵ turbulence model with a sector model including the creviced piston. The creviced piston is used in the experimental setup to reduce boundary layer effects and to maintain a homogeneous core in the reaction cylinder. Computational fluid dynamics simulations are conducted for different gasoline-ethanol fuel blends from E10 (10% ethanol v/v) to E100. The fuel blend is modeled as a surrogate mixture of toluene, iso-octane, n-heptane for gasoline content, and ethanol. The computational results were validated against experimental results using pressure measurements and laser extinction diagnostics. Different soot models are investigated to evaluate their capability of predicting the sooting tendencies of fuel blends, especially in richer conditions experienced during mixing-controlled combustion. The experimental combustion characteristics such as the ignition delay of different blends of fuel are reasonably well predicted. The Particulate Size Mimic (PSM) model accurately predicts the soot generation characteristics of the different fuels, but the Hiroyasu-NSC model falls short in this regard. For accurate prediction of soot with the PSM model, the thermodynamic conditions during combustion must be accurately modeled. While the current computational modeling tools can produce accurate results for the prediction of particulate matter emissions, there is much work to be done in improving our understanding of the underlying fundamental processes.

Needleless connectors were introduced into clinical practice to reduce the rate of needlestick injuries to healthcare workers (HCWs). There have, however, been limited reports of user acceptability of these devices. The usability and acceptability of the Clearlink needleless connector (Baxter Healthcare, UK) was therefore completed by HCWs at University Hospital Birmingham NHS Foundation Trust following a 12-month clinical evaluation. Seventy per cent (28/40) of HCWs reported that they would prefer to use Clearlink needleless connectors rather than conventional luers caps, 15% (6/40) would use either, and only 15% (6/40) preferred to use luer caps. In total, 85% of HCWs reported that Clearlink was acceptable to use in the clinical situation. The results demonstrate that comprehensive training and technical support both before and after new device implementation were essential to ensure a smooth transition. [ABSTRACT FROM AUTHOR]

Improvements in cancer therapy have led to increased patient survival times in spite of metastatic spinal disease in many forms of cancer. Conventional treatment methods often employ radiotherapy with or without surgery depending on the neurological status, mechanical instability, and the extent of tumor. Percutaneous vertebroplasty as well as stereotactic radiosurgery (SRS) have arisen as common modalities of treatment of spinal metastasis in which neurological compromise or spinal instability and deformity is not of significant concern. These treatments, when used in combination, have been shown to provide early pain relief and effective tumor control while avoiding surgical resection, fixation, and lengthy recovery times. We present a case unique in the literature for the use of this combination treatment for tumors of the C2 vertebral body. While limited in application to patients without overt atlantoaxial instability or significant spinal canal compromise, we believe it provides a significant benefit in decreasing morbidity and improving early adherence to systemic therapy.

Background: Normothermic machine perfusion of donor livers has become standard practice in the field of transplantation, allowing the assessment of organs and safe extension of preservation times. Alongside its clinical uses, there has been expanding interest in extended normothermic machine perfusion (eNMP) of livers as a potential vehicle for medical research. Reproducible extended normothermic machine perfusion has remained elusive due to its increased complexity and monitoring requirements. We set out to develop a reproducible protocol for the extended normothermic machine perfusion of whole human livers., Methods: Human livers declined for transplantation were perfused using a blood-based perfusate at 36 °C using the Liver Assist device (XVIVO, Sweden), with continuous veno-venous haemofiltration in-parallel. We developed the protocol in a stepwise fashion., Results: Perfusion techniques utilised included: targeted physiological vascular flows, phosphate replacement (to prevent hypophosphataemia), N-acetylcysteine (to prevent methaemoglobin accumulation), and the utilisation of sodium lactate as both a nutritional source and real-time measure of hepatocyte function. All five human livers perfused with the developed protocol showed preserved function with a median perfusion time of 168 h (range 120-184 h), with preserved viability throughout., Conclusions: Livers can be reproducibly perfused in excess of 120 (range 121-184) hours with evidence of preserved hepatocyte and cholangiocyte function., (© 2024. The Author(s).)

Extended duration of normothermic machine perfusion (NMP) provides opportunities to resuscitate suboptimal donor livers. This intervention requires adequate oxygen delivery typically provided by a blood-based perfusion solution. Methaemoglobin (MetHb) results from the oxidation of iron within haemoglobin and represents a serious problem in perfusions lasting > 24 h. We explored the effects of anti-oxidant, N-acetylcysteine (NAC) on the accumulation of methaemoglobin. NMP was performed on nine human donor livers declined for transplantation: three were perfused without NAC (no-NAC group), and six organs perfused with an initial NAC bolus, followed by continuous infusion (NAC group), with hourly methaemoglobin perfusate measurements. In-vitro experiments examined the impact of NAC (3 mg) on red cells (30 ml) in the absence of liver tissue. The no-NAC group sustained perfusions for an average of 96 (range 87-102) h, universally developing methaemoglobinaemia (≥ 2%) observed after an average of 45 h, with subsequent steep rise. The NAC group was perfused for an average of 148 (range 90-184) h. Only 2 livers developed methaemoglobinaemia (peak MetHb of 6%), with an average onset of 116.5 h. Addition of NAC efficiently limits formation and accumulation of methaemoglobin during NMP, and allows the significant extension of perfusion duration., (© 2023. The Author(s).)

Background: Evidence supporting venous thromboembolism (VTE) prophylaxis with direct oral anticoagulants (DOACs) in patients with nephrotic syndrome (NS) is limited to case reports., Objective: The purpose of this study was to compare bleeding and thromboembolic events in this population., Methods: A retrospective cohort study was conducted in adults with NS initiated on a DOAC or warfarin for VTE prophylaxis between January 2013 and July 2021 within the Ochsner Health System. Patients with study drug exposure within the preceding 7 days, acute VTE within the preceding 6 months, or ≤7 days of study drug exposure were excluded. The primary outcome was the composite rate of major bleeding and clinically relevant nonmajor bleeding. Secondary outcomes included time to major bleeding and rate of new thromboembolic events. This study was approved by the Ochsner Health System Institutional Review Board., Results: Twenty-five DOAC and 19 warfarin patients were included. The primary outcome occurred in 8% vs 26.3% ( P = 0.21) of patients treated with a DOAC or warfarin, respectively, and was driven by major bleeding (4% vs 21%, P = 0.25). Other secondary outcomes were similar between cohorts. The study was limited by a small sample size., Conclusion and Relevance: Use of DOACs for VTE prophylaxis resulted in a nonstatistically significant, but clinically relevant lower rate of major bleeding compared to warfarin. This study provides comparative data showing safe and effective use of DOACs in patients with NS. Prospective, randomized studies are needed to confirm results.

Background: SARS-CoV-2 can spread rapidly on maritime platforms. Several outbreaks of SARS-CoV-2 have been reported on warships at sea, where transmission is facilitated by living and working in close quarters. Core components of infection control measures such as social distancing, patient isolation and quarantine of exposed persons are extremely difficult to implement. Whole genome sequencing (WGS) of SARS-CoV-2 has facilitated epidemiological investigations of outbreaks, impacting on outbreak management in real time by identifying transmission patterns, clusters of infection and guiding control measures. We suggest such a capability could mitigate against the impact of SARS-CoV-2 in maritime settings., Methods: We set out to establish SARS-CoV-2 WGS using miniaturised nanopore sequencing technology aboard the Royal Fleet Auxiliary ARGUS while at sea. Objectives included designing a simplified protocol requiring minimal reagents and processing steps, the use of miniaturised equipment compatible for use in limited space, and a streamlined and standalone data analysis capability to allow rapid in situ data acquisition and interpretation., Results: Eleven clinical samples with blinded SARS-CoV-2 status were tested at sea. Following viral RNA extraction and ARTIC sequencing library preparation, reverse transcription and ARTIC PCR-tiling were performed. Samples were subsequently barcoded and sequenced using the Oxford Nanopore MinION Mk1B. An offline version of the MinKNOW software was used followed by CLC Genomics Workbench for downstream analysis for variant identification and phylogenetic tree construction. All samples were correctly classified, and relatedness identified., Conclusions: It is feasible to establish a small footprint sequencing capability to conduct SARS-CoV-2 WGS in a military maritime environment at sea with limited access to reach-back support. This proof-of-concept study has highlighted the potential of deploying such technology in the future to military environments, both maritime and land-based, to provide meaningful clinical data to aid outbreak investigations., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Evidence for direct oral anticoagulants (DOACs) in patients with cirrhosis is limited. Few patients with Child-Turcotte-Pugh (CTP) class B and C cirrhosis have been studied., Objective: To compare major bleeding rates in patients with cirrhosis receiving a DOAC versus warfarin., Methods: A retrospective cohort study was conducted in adults with cirrhosis receiving a DOAC versus warfarin for venous thromboembolism, portal-vein thrombosis, or atrial fibrillation. The primary outcome was the rate of major bleeding. Secondary outcomes included time to major bleeding, clinically relevant nonmajor bleeding, all bleeding, gastrointestinal bleeding, intracranial bleeding, and new thromboembolic events. The study was approved by the Ochsner Health System Institutional Review Board., Results: A total of 44 patients receiving a DOAC and 41 patients receiving warfarin were included. Major bleeding occurred in 4 patients receiving a DOAC and 6 patients receiving warfarin (9.1% vs 14.6%; P = 0.881). Rates of major bleeding were similar in 24 DOAC and 17 warfarin patients with CTP Class B (4.2% vs 17.6%; P = 0.37) and 8 DOAC and 9 warfarin patients with CTP Class C (37.5% vs 11.1%; P = 0.41) cirrhosis. Secondary bleeding and efficacy outcomes were similar between cohorts. The study was limited by a small sample size., Conclusion and Relevance: Treatment with DOACs in patients with cirrhosis was associated with a similar rate of major bleeding compared with warfarin. Inclusion of CTP class C patients in future studies remains valuable to evaluate safety and efficacy of DOACs in this population.

Background: The use of mechanical bowel preparation and prophylaxis with oral antimicrobial agents can prevent surgical site infection (SSI) in colorectal surgical procedures, but routine adoption of these and other practices by surgeons has been limited. The aim of this study was to determine the actual practice and surgeon beliefs about preventative measures in elective colorectal operations and to compare them with established recommendations. Methods: Web-based survey was sent to colorectal surgeons assessing knowledge, beliefs, and practices regarding the use of preventative measures for SSI. Results: Of 355 surgeons, 33% had no feedback of SSI rate; 60% believed in evidence for normothermia, wound edge protection, and use of alcohol solution, and reported use of these strategies. There was a discrepancy in the assumed evidence and use of hyperoxia, glove replacement after anastomosis, surgical tools replacement, and saline surgical site lavage. Most of respondents believe that oral antibiotic prophylaxis diminishes infection, but is indicated only by one third of them. Few surgeons believe in MBP, but many actually use it. Most surgeons believe that there is a discrepancy between published guidelines and actual clinical practice. As proper means to implement guidelines, checklists, standardized orders, surveillance, feedback of SSI rates, and educational programs are rated most highly by surgeons, but few of these are in place at their institutions. Conclusions: Gaps in the translation of evidence into practice remain in the prevention of SSI in colorectal surgical procedures. Several areas for improvement have been identified. Specific implementation strategies should be addressed in colorectal units.

Background: Central venous catheters (CVCs) are commonly secured with sutures which are associated with microbial colonization and infection. We report a comparison of a suture-free system with standard sutures for securing short-term CVC in an international multicentre, prospective, randomized, non-blinded, observational feasibility study. Consented critical care patients who had a CVC inserted as part of their clinical management were randomized to receive either sutures or the suture-free system to secure their CVC. The main outcome measures were CVC migration (daily measurement of catheter movement) and unplanned catheter removals., Results: The per cent of unplanned CVC removal in the two study groups was 2% (suture group 2 out of 86 patients) and 6% (suture-free group 5 out of 85 patients). Both securement methods were well tolerated in terms of skin irritation. The time and ease of application and removal of either securement systems were not rated significantly different. There was also no significant difference in CVC migration between the two securement systems in exploratory univariate and multivariate analyses. Overall, 42% (36 out of 86) of the CVC secured with sutures and 56% (48 out of 85) of the CVC secured with the suture-free securement system had CVC migration of ≥ 2 mm., Conclusions: The two securement systems performed similarly in terms of CVC migration and unplanned removal of CVC; however, the feasibility study was not powered to detect statistically significant differences in these two parameters., Trial Registration: ISRCTN, ISRCTN13939744. Registered 9 July 2015, http://www.isrctn.com/ISRCTN13939744 .

Background: Because of a lack of comparative data on anticoagulant use in the advanced chronic kidney disease (CKD) population, guidelines recommend warfarin for atrial fibrillation and venous thromboembolism (VTE) treatment in these patients. However, apixaban has specific dosing recommendations in CKD leading to use in clinical practice., Objective: To evaluate major bleeding, stroke, and thromboembolism rates in patients with CKD stage 4, stage 5, and dialysis on apixaban or warfarin therapy., Methods: This was a retrospective cohort study of patients with advanced CKD receiving apixaban or warfarin. The primary outcome was the occurrence of major bleeding at 3 months after enrollment. Secondary outcomes included occurrence of major bleeding, occurrence of ischemic stroke, and recurrence of VTE at 3 to 6 and 6 to 12 months., Results: A total of 604 patients were included in the analysis. The percentage of apixaban and warfarin patients with a major bleed at 0 to 3, 3 to 6, and 6 to 12 months were 8.3% versus 9.9% ( P=0.48), 1.4% versus 4% ( P=0.07), and 1.5% versus 8.4% ( P<0.001), respectively. There were no differences in rates of ischemic stroke or recurrent VTE at any time period. Conclusion and Relevance: Patients with advanced CKD taking apixaban had similar bleeding rates at 3 months compared with those taking warfarin. However, those who continued therapy had higher major bleeding rates with warfarin between 6 and 12 months. This study provides knowledge on the effects of a direct oral anticoagulant in a population that was excluded from all major trials.

Background: The knowledge of the grade of implementation of preventative measures for surgical site infection (SSI) is crucial prior to planning dissemination strategies., Methods: Online survey among the members of the Spanish Association of Surgeons (AEC) to know the actual application of measures, and to compare them with new recommendations issued by international organizations., Results: Most of the 835 responding surgeons work in National Health Service Hospitals (91.3%). Surgeons of all super-specialties answered. 90.4% of responders recommend a preoperative shower, with normal soap or chlorhexidine. 60% recommend hair removal, preferably clipping, although 30% still recommend shaving. Povidone-iodine in aqueous solution or chlorhexidine in alcohol are used for skin preparation. Only 51.9% of surgeons allow solution to air drying before applying surgical drapes. In 83.2% of cases surgeons operate with a single pair of gloves. Perioperative normothermia and hyperoxia were used in 92% and 27.9% of cases, respectively. At the end of the procedure, peritoneal and wound lavage are used, in most cases with saline. Antimicrobial impregnated sutures are rarely used (85.7%) by surgeons, and 32% occasionally use negative pressure therapy on the closed wound., Conclusions: There is great variability in the level of awareness and application of the main measures of SSI prevention among Spanish surgeons. Several areas for improvement have been detected, as core prevention measures are not in common use, and discontinued practices are continued to be used. These practices should be addressed by the AEC by drafting specific recommendations for the prevention of SSI in Spanish hospitals., (Copyright © 2018 IJS Publishing Group Ltd. All rights reserved.)

Background: The optimal decontamination method for needle-free connectors is still unresolved. The objective of this study was to determine if a continuous passive disinfection cap is as effective as standard cleaning for the microbial decontamination of injection ports of two types of needle-free connectors., Methods: The injection ports of needle-free connectors were inoculated with Staphylococcus aureus and allowed to dry. Disinfection caps containing 70% ( v / v ) isopropyl alcohol (IPA) were attached to the connectors for one, three or 7 days and were compared with needle-free connectors cleaned with 2% ( w / v ) chlorhexidine gluconate (CHG) in 70% ( v/v ) IPA. The number of S. aureus remaining on the injection ports was evaluated. Median log 10 reductions and 95% confidence interval (CI) were calculated and data analyzed using the Mann-Whitney test., Results: The application of the disinfection cap resulted in a significantly higher reduction in S. aureus than the 2% ( w / v ) CHG in 70% ( v / v ) IPA wipe, achieving a > 5 Log 10 reduction in CFU at each time point., Conclusions: The disinfection caps resulted in a significantly higher reduction in S.aureus on the injection ports when compared to the use of a 2% ( w/v ) CHG in 70% ( v/v ) IPA wipe. This offers an explanation for the lower rates of central-line associated bloodstream infection (CLABSI) associated with the use of disinfection caps reported in clinical studies., Competing Interests: Not applicableNot applicableTSJE and ALC have received honoraria from BD for attendance at advisory board meetings and presentations at symposia. TSJE and TJK have received honoraria from 3 M for attendance at advisory board meetings and presentations at symposia. PN has no conflicts to declare. This work was presented in part as a poster at the 5th World Congress on Vascular Access, June 20-22 2018, Copenhagen, Denmark.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Background: needle-free connectors are widely used in clinical practice. The aim of this study was to identify any differences between microbial ingress into six different connectors (three neutral-displacement, one negative-displacement and two anti-reflux connectors)., Methods: each connector underwent a 7-day clinical simulation involving repeated microbial contamination of the connector's injection ports with Staphylococcus aureus followed by decontamination and then saline flushes through each connector. The simulation was designed to be a surrogate marker for the potential risk of contamination in clinical practice., Results: increasing numbers of S. aureus were detected in the flushes over the 7 days of sampling despite adherence to a rigorous decontamination programme. Significant differences in the number of S. aureus recovered from the saline flush of some types of connectors were also detected. Two different durations (5- and 15-second) of decontamination of the injection ports with 70% isopropyl alcohol (IPA) wipes were also investigated. There was no significant difference between the median number of S. aureus recovered in the saline flushes following a 5-second (165.5, 95% CI=93-260) or a 15-second decontamination regimen (75, 10-190)., Conclusions: The findings suggest that there may be differences in the risk of internal microbial contamination with different types of connectors and that even 15 seconds of decontamination may not fully eradicate microorganisms from the injection ports of some devices.