Enabling strain imaging in realistic Eulerian ultrasound simulation methods

Cardiovascular strain imaging is continually improving due to ongoing advances in ultrasound acquisition and data processing techniques. The phantoms used for validation of new methods are often burdensome to make and lack flexibility to vary mechanical and acoustic properties. Simulations of US imaging provide an alternative with the required flexibility and ground truth strain data. However, the current Lagrangian US strain imaging models cannot simulate heterogeneous speed of sound distributions and higher-order scattering, which limits the realism of the simulations. More realistic Eulerian modelling techniques exist but have so far not been used for strain imaging. In this research, a novel sampling scheme was developed based on a band-limited interpolation of the medium, which enables accurate strain simulation in Eulerian methods. The scheme was validated in k-Wave using various numerical phantoms and by a comparison with Field II. The method allows for simulations with a large range in strain values and was accurate with errors smaller than −60 dB. Furthermore, an excellent agreement with the Fourier theory of US scattering was found. The ability to perform simulations with heterogeneous speed of sound distributions was demonstrated using a pulsating artery model. The developed sampling scheme contributes to more realistic strain imaging simulations, in which the effect of heterogenous acoustic properties can be taken into account

Adequate debridement and drainage of the mediastinum using open thoracotomy or video-assisted thoracoscopic surgery for Boerhaave’s syndrome

Background Boerhaave's syndrome has a high mortality rate (14-40%). Surgical treatment varies from a minimal approach consisting of adequate debridement with drainage of the mediastinum and pleural cavity to esophageal resection. This study compared the results between a previously preferred open minimal approach and a video-assisted thoracoscopic surgery (VATS) procedure currently considered the method of choice. Methods In this study, 12 consecutive patients treated with a historical nonresectional drainage approach (1985-2001) were compared with 12 consecutive patients treated prospectively after the introduction of VATS during the period 2002-2009. Baseline characteristics were equally distributed between the two groups. Results In the prospective group, 2 of the 12 patients had the VATS procedure converted to an open thoracotomy, and 2 additional patients were treated by open surgery. In the prospective group, 8 patients experienced postoperative complications compared with all 12 patients in the historical control group. Four patients (17%), two in each group, underwent reoperation. Six patients, three in each group, were readmitted to the hospital. The overall in-hospital mortality was 8% (1 patient in each group), which compares favorably with other reports (7-27%) based on drainage alone. Conclusions Adequate surgical debridement with drainage of the mediastinum and pleural cavity resulted in a low mortality rate. The results for VATS in this relatively small series were comparable with those for an open thoracotomy

Maximum Photosynthetic Yield of Green Microalgae in Photobioreactors

The biomass yield on light energy of Dunaliella tertiolecta and Chlorella sorokiniana was investigated in a 1.25- and 2.15-cm light path panel photobioreactor at constant ingoing photon flux density (930 µmol photons m−2 s−1). At the optimal combination of biomass density and dilution rate, equal biomass yields on light energy were observed for both light paths for both microalgae. The observed biomass yield on light energy appeared to be based on a constant intrinsic biomass yield and a constant maintenance energy requirement per gram biomass. Using the model of Pirt (New Phytol 102:3–37, 1986), a biomass yield on light energy of 0.78 and 0.75 g mol photons−1 and a maintenance requirement of 0.0133 and 0.0068 mol photons g−1 h−1 were found for D. tertiolecta and C. sorokiniana, respectively. The observed yield decreases steeply at low light supply rates, and according to this model, this is related to the increase of the amount of useable light energy diverted to biomass maintenance. With this study, we demonstrated that the observed biomass yield on light in short light path bioreactors at high biomass densities decreases because maintenance requirements are relatively high at these conditions. All our experimental data for the two strains tested could be described by the physiological models of Pirt (New Phytol 102:3–37, 1986). Consequently, for the design of a photobioreactor, we should maintain a relatively high specific light supply rate. A process with high biomass densities and high yields at high light intensities can only be obtained in short light path photobioreactors

Influence of Reoperations on Long-Term Quality of Life After Restrictive Procedures: A Prospective Study

Quality of life improves after bariatric surgery. However, long-term results and the influence of reoperations are not well known. A prospective quality of life assessment before, 1 and 7 years after laparoscopic adjustable gastric banding (LAGB) and vertical banded gastroplasty (VBG) was performed in order to determine the influence of reoperations during follow-up. One hundred patients were included in the study. Fifty patients underwent VBG and 50 LAGB. Patients completed the quality of life questionnaires prior to surgery and two times during follow-up. Health-related quality of life (HRQoL) questionnaires included the Nottingham Health Profile I and II and the Sickness Impact Profile 68. Follow-up was 84% with a mean duration of 84 months (7 years). During follow-up, 65% of VBG patients underwent conversion to Roux-en-Y gastric bypass while 44% of LAGB patients underwent a reoperation or conversion. One year after the procedure, nearly all quality-of-life parameters significantly improved. After 7 years, the Nottingham Health Profile (NHP)-I domain “physical ability”, the NHP-II and the SIP-68 domains “mobility control”, “social behavior”, and “mobility range” were still significantly improved in both groups. The domains “emotional reaction”, “social isolation” (NHP-I), and “emotional stability” (SIP-68) remained significantly improved in the VBG group while this was true for the domain “energy level” (NHP-I) in the LAGB group. Both the type of procedure and reoperations during follow-up were not of significant influence on the HRQoL results. Weight loss and decrease in comorbidities were the only significant factors influencing quality of life. Restrictive bariatric surgery improves quality of life. Although results are most impressive 1 year after surgery, the improvement remains significant after long-term follow-up. Postoperative quality of life is mainly dependent on weight loss and decrease in comorbidities and not on the type of procedure or surgical complications

Development and Validation of a Prediction Model for 1-Year Mortality in Patients With a Hematologic Malignancy Admitted to the ICU

OBJECTIVES: To develop and validate a prediction model for 1-year mortality in patients with a hematologic malignancy acutely admitted to the ICU. DESIGN: A retrospective cohort study. SETTING: Five university hospitals in the Netherlands between 2002 and 2015. PATIENTS: A total of 1097 consecutive patients with a hematologic malignancy were acutely admitted to the ICU for at least 24 h. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We created a 13-variable model from 22 potential predictors. Key predictors included active disease, age, previous hematopoietic stem cell transplantation, mechanical ventilation, lowest platelet count, acute kidney injury, maximum heart rate, and type of malignancy. A bootstrap procedure reduced overfitting and improved the model's generalizability. This involved estimating the optimism in the initial model and shrinking the regression coefficients accordingly in the final model. We assessed performance using internal-external cross-validation by center and compared it with the Acute Physiology and Chronic Health Evaluation II model. Additionally, we evaluated clinical usefulness through decision curve analysis. The overall 1-year mortality rate observed in the study was 62% (95% CI, 59-65). Our 13-variable prediction model demonstrated acceptable calibration and discrimination at internal-external validation across centers ( C-statistic 0.70; 95% CI, 0.63-0.77), outperforming the Acute Physiology and Chronic Health Evaluation II model ( C-statistic 0.61; 95% CI, 0.57-0.65). Decision curve analysis indicated overall net benefit within a clinically relevant threshold probability range of 60-100% predicted 1-year mortality. CONCLUSIONS: Our newly developed 13-variable prediction model predicts 1-year mortality in hematologic malignancy patients admitted to the ICU more accurately than the Acute Physiology and Chronic Health Evaluation II model. This model may aid in shared decision-making regarding the continuation of ICU care and end-of-life considerations

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

Colorectal liver metastases: Surgery versus thermal ablation (COLLISION) - a phase III single-blind prospective randomized controlled trial

Background: Radiofrequency ablation (RFA) and microwave ablation (MWA) are widely accepted techniques to eliminate small unresectable colorectal liver metastases (CRLM). Although previous studies labelled thermal ablation inferior to surgical resection, the apparent selection bias when comparing patients with unresectable disease to surgical candidates, the superior safety profile, and the competitive overall survival results for the more recent reports mandate the setup of a randomized controlled trial. The objective of the COLLISION trial is to prove non-inferiority of thermal ablation compared to hepatic resection in patients with at least one resectable and ablatable CRLM and no extrahepatic disease. Methods: In this two-arm, single-blind multi-center phase-III clinical trial, six hundred and eighteen patients with at least one CRLM (≤3cm) will be included to undergo either surgical resection or thermal ablation of appointed target lesion(s) (≤3cm). Primary endpoint is OS (overall survival, intention-to-treat analysis). Main secondary endpoints are overall disease-free survival (DFS), time to progression (TTP), time to local progression (TTLP), primary and assisted technique efficacy (PTE, ATE), procedural morbidity and mortality, length of hospital stay, assessment of pain and quality of life (QoL), cost-effectiveness ratio (ICER) and quality-adjusted life years (QALY). Discussion: If thermal ablation proves to be non-inferior in treating lesions ≤3cm, a switch in treatment-method may lead to a reduction of the post-procedural morbidity and mortality, length of hospital stay and incremental costs without compromising oncological outcome for patients with CRLM. Trial registration:NCT03088150 , January 11th 2017

How do we get the adoption of electric vehicles into a higher gear in Europe?

The world is under the spell of the energy transition due to climate change. In 2015 197 parties agreed to the Paris-agreement, settings goals for limiting global warming. The transportation sector contributes for almost 25% of all global greenhouse gas emissions (GHG). A promising pathway to decrease emissions from fossil fuels in the transportation sector is to replace conventional internal combustion engines (ICE) with Battery Electric Vehicles (BEV).This thesis analyses how the introduction of BEVs in Europe can be accelerated. Five countries were selected and categorised, based on Rogers' diffusion of innovation theory.Based on a literature analysis, the factors influencing the adoption of the BEV were identified and selected. From these factors, an analytical research model was created. This analytical research model was applied to each country in order to compare the countries and draw conclusions. The analytical model consisted of the factors: government regulations and incentives, purchase price, total cost of ownership, charging infrastructure, model availability, consumer characteristics and BEV adoption.The study concluded that governments have two tools to stimulate the BEV adoption: make the BEV cost effective compared to the ICE and stimulate the charging infrastructure. If it is financially more attractive to drive a BEV in a country than an ICE, this will have a major impact on BEV adoption. Making the BEV financially attractive can be done with tax measures and subsidies. In general, countries with relatively high car taxes can make BEVs more financially attractive than countries with relatively low car taxes, which results in a higher BEV adoptionIn addition, a country must ensure that the charging infrastructure grows along with the BEV adoption. In general, it is a pre-condition to develop its slow charger network to stimulate BEV adoption. However, it depends on the country how the slow charger network should be set up. An indicator for this is the percentage of detached houses. If this percentage is high, a country must focus on private charging when setting up its slow charging network. With a low percentage of detached houses, a country must focus on public charging when setting up the slow charging network. Furthermore, it is expected that private parties will jump into the fast charging market. These private parties will only step in if a country has a relatively high BEV adoption, such as Norway and the Netherlands, because it is only then profitable. The study also shows that in countries with a large surface area, it is a precondition to develop its fast charging network. Therefore, when a country has a low BEV adoption, but a large surface, incentives are needed from the government to stimulate a fast charging network.A financial attractive BEV environment and a well-developed charging infrastructure has as consequence in increasing the number of BEV models. When more BEV models enter the market in a country, consumers have more choice, and this has a stimulating effect on BEV adoption in a country.Management of Technology (MoT