The safety and efficacy of laparoscopic retrograde appendicectomy, base-to-tip approach

BackgroundLaparoscopic appendicectomy is one of the most frequently performed surgical procedures worldwide. There is limited evidence evaluating the role and safety of laparoscopic retrograde appendicectomy (LRA), base to tip approach, compared to standard laparoscopic antegrade appendicectomy (LAA), tip to base approach. This study aims to assess the safety of LRA compared to LAA in terms of intra-abdominal collection (IAC) rate and using Sunshine Appendicitis Grading System (SAGS).MethodsRecords of two-hundred and seventy-three patients undergoing laparoscopic appendicectomy by LAA and LRA approaches were analysed. The severity of appendicitis was rated using a standardised Sunshine Appendicitis Grading System (SAGS) score intra-operatively. The primary outcome measure was the occurrence of an intra-abdominal collection, and secondary measures were procedure time, post-operative length of stay and other complications.ResultsOf the two-hundred and seventy-three patients, there were two patients who developed an intra-abdominal collection. Both patients were in the LAA group with SAGS IV scores. Between SAGS IV patients, Chi-squared p value of 0.6691. Therefore, there was no statically significant difference in the intra-abdominal collection (IAC) rate between LAA and LRA groups from this study.ConclusionsThe current study has shown that laparoscopic retrograde appendicectomy (LRA) does not increase risk of intra-abdominal collection compared to laparoscopic antegrade appendicectomy (LAA) within the limit of this study

Inhibition of Droplet Growth in Model Beverage Emulsions Stabilized Using Poly (ethylene glycol) Alkyl Ether Surfactants Having Various Hydrophilic Head Sizes: Impact of Ester Gum

The effect of ester gum, a widely used weighting agent, on Ostwald ripening in model beverage emulsions formulated using different food-grade surfactants was examined. A microfluidizer was used to prepare 5% orange oil-in-water emulsions stabilized by a series of ethylene glycol alkyl ether surfactants. Emulsions prepared using only orange oil exhibited an appreciable increase in droplet size during a 14-day storage, independent of surfactant type or concentration. Incorporation of ester gum into the oil phase of the emulsions effectively inhibited droplet growth at concentrations ≥20%. The inhibition of droplet growth by ester gum depended on the surfactant type (hydrophilic group size) and concentration. Overall, ester gum stabilized the emulsions by acting as an Ostwald ripening inhibitor, as well as a weighting agent

Acoustic streaming in a soft tissue microenvironment

We demonstrated that sound can push fluid through a tissue-mimicking material. Although acousticstreaming in tissue has been proposed as a mechanism for biomedical ultrasound applications, such as neuromodu-lation and enhanced drug penetration, streaming in tissue or acoustic phantoms has not been directly observed. Wedeveloped a material that mimics the porous structure of tissue and used a dye and a video camera to track fluidmovement. When applied above an acoustic intensity threshold, a continuous focused ultrasound beam (spatialpeak time average intensity: 238 W/cm2, centre frequency: 5 MHz) was found to push the dye axially, that is, in thedirection of wave propagation and in the radial direction. Dye clearance increased with ultrasound intensity andwas modelled using an adapted version of Eckart’s acoustic streaming velocity equation. No microstructuralchanges were observed in the sonicated region when assessed using scanning electron microscopy. Our study indi-cates that acoustic streaming can occur in soft porous materials and provides a mechanistic basis for future use ofstreaming for therapeutic or diagnostic purposes.WOS:000451607300022Scopus - Affiliation ID: 60105072PMID: 30336964Science Citation Index ExpandedQ1 - Q2ArticleUluslararası işbirliği ile yapılan - EVETOcak2019YÖK - 2018-1

Thermoelectric Generators with High Potential for Waste Heat Recovery in Heavy-Duty Vehicle Applications: Validation by a Functional Prototype with up to 2.7 kW

This research study demonstrates the engineering and measurement of a TEG prototype for heavyduty vehicles applications. The thermoelectric module area corresponds to approximately 1370 cm2 and consists of 144 segmented thermoelectric high-power modules based on bismuth telluride and skutterudite. The experimental setup enables the validation of the technology thermoelectric up to technology readiness level 5, which is rare in scientific publications on a 1:1 scale. The measured performance data of a functional prototype will be presented, as well as the electrical output power and compared with the simulated values. As a result, the simulative holistic design method of thermoelectric generators developed at the DLR Institute of Vehicle Concepts is successfully verified. In the measurement points performed, the accuracy of the simulated temperatures reaches in average more than 98%. The accuracy of the simulated output power is in average more than 94% and the minimum deviation is only -0.5%. The maximum electrical output power of 2,700 W could be measured at hot gas inlet temperature of 745 °C, mass flow of 0.25 kg/s, coolant inlet temperature of 20 °C and volume flow of 0.5 dm3/s. A significant improvement in the system level of thermoelectric generators for heavy-duty vehicles could be reached and the power density of the system could be increased to 174 W/kg and 326 W/dm3 compared to the state of the art based on the experimental measured values

Melphalan modifies the bone microenvironment by enhancing osteoclast formation

Melphalan is a cytotoxic chemotherapy used to treat patients with multiple myeloma (MM). Bone resorption by osteoclasts, by remodeling the bone surface, can reactivate dormant MM cells held in the endosteal niche to promote tumor development. Dormant MM cells can be reactivated after melphalan treatment; however, it is unclear whether melphalan treatment increases osteoclast formation to modify the endosteal niche. Melphalan treatment of mice for 14 days decreased bone volume and the endosteal bone surface, and this was associated with increases in osteoclast numbers. Bone marrow cells (BMC) from melphalan-treated mice formed more osteoclasts than BMCs from vehicle-treated mice, suggesting that osteoclast progenitors were increased. Melphalan also increased osteoclast formation in BMCs and RAW264.7 cells in vitro, which was prevented with the cell stress response (CSR) inhibitor KNK437. Melphalan also increased expression of the osteoclast regulator the microphthalmia-associated transcription factor (MITF), but not nuclear factor of activated T cells 1 (NFATc1). Melphalan increased expression of MITF-dependent cell fusion factors, dendritic cell-specific transmembrane protein (Dc-stamp) and osteoclast-stimulatory transmembrane protein (Oc-stamp) and increased cell fusion. Expression of osteoclast stimulator receptor activator of NFκB ligand (RANKL) was unaffected by melphalan treatment. These data suggest that melphalan stimulates osteoclast formation by increasing osteoclast progenitor recruitment and differentiation in a CSR-dependent manner. Melphalan-induced osteoclast formation is associated with bone loss and reduced endosteal bone surface. As well as affecting bone structure this may contribute to dormant tumor cell activation, which has implications for how melphalan is used to treat patients with MM

Immunogenicity and seroefficacy of 10-valent and 13-valent pneumococcal conjugate vaccines: a systematic review and network meta-analysis of individual participant data

Background: Vaccination of infants with pneumococcal conjugate vaccines (PCV) is recommended by the World Health Organization. Evidence is mixed regarding the differences in immunogenicity and efficacy of the different pneumococcal vaccines. Methods: In this systematic-review and network meta-analysis, we searched the Cochrane Library, Embase, Global Health, Medline, clinicaltrials.gov and trialsearch.who.int up to February 17, 2023 with no language restrictions. Studies were eligible if they presented data comparing the immunogenicity of either PCV7, PCV10 or PCV13 in head-to-head randomised trials of young children under 2 years of age, and provided immunogenicity data for at least one time point after the primary vaccination series or the booster dose. Publication bias was assessed via Cochrane's Risk Of Bias due to Missing Evidence tool and comparison-adjusted funnel plots with Egger's test. Individual participant level data were requested from publication authors and/or relevant vaccine manufacturers. Outcomes included the geometric mean ratio (GMR) of serotype-specific IgG and the relative risk (RR) of seroinfection. Seroinfection was defined for each individual as a rise in antibody between the post-primary vaccination series time point and the booster dose, evidence of presumed subclinical infection. Seroefficacy was defined as the RR of seroinfection. We also estimated the relationship between the GMR of IgG one month after priming and the RR of seroinfection by the time of the booster dose. The protocol is registered with PROSPERO, ID CRD42019124580. Findings: 47 studies were eligible from 38 countries across six continents. 28 and 12 studies with data available were included in immunogenicity and seroefficacy analyses, respectively. GMRs comparing PCV13 vs PCV10 favoured PCV13 for serotypes 4, 9V, and 23F at 1 month after primary vaccination series, with 1.14- to 1.54- fold significantly higher IgG responses with PCV13. Risk of seroinfection prior to the time of booster dose was lower for PCV13 for serotype 4, 6B, 9V, 18C and 23F than for PCV10. Significant heterogeneity and inconsistency were present for most serotypes and for both outcomes. Two-fold higher antibody after primary vaccination was associated with a 54% decrease in risk of seroinfection (RR 0.46, 95% CI 0.23–0.96). Interpretation: Serotype-specific differences were found in immunogenicity and seroefficacy between PCV13 and PCV10. Higher antibody response after vaccination was associated with a lower risk of subsequent infection. These findings could be used to compare PCVs and optimise vaccination strategies. Funding: The NIHR Health Technology Assessment Programme

Graphite-anchored lithium vanadium oxide as anode of lithium ion battery

Graphite-anchored lithium vanadium oxide (Li1.1V0.9O2) has been synthesized via a “one-pot” in situ method. The effects of the synthesis conditions, such as the ratio of reaction components and calcination temperature, on the electrochemical performance are systematically investigated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), galvanostatic discharge/charge tests and differential scanning calorimetry (DSC). Compared with the simple mixture of graphite and lithium vanadium oxide, the graphite-anchored lithium vanadium oxide delivers an enhanced reversible capacity, rate capability and cyclic stability. It also shows better thermal stability.Web of Scienc