Anastomotic leak in ovarian cancer cytoreduction surgery: a systematic review and meta-analysis

Introduction: Anastomotic leaks (AL) following ovarian cytoreduction surgery could be detrimental, leading to significant delays in commencing adjuvant chemotherapy, prolonged hospital stays and increased morbidity. The aim of this study was to investigate risk factors associated with anastomotic leaks after ovarian cytoreduction surgery. Material and methods: The MEDLINE (via PubMed), Cochrane Library, EMBASE and Scopus bibliographical databases were searched. Original clinical studies investigating risk factors for AL in ovarian cytoreduction surgery were included. Results: Eighteen studies with non-overlapping populations reporting on patients undergoing cytoreduction surgery for ovarian cancer (n = 4622, including 344 cases complicated by AL) were included in our analysis. Patients undergoing ovarian cytoreduction surgery complicated by AL had a significantly higher rate of 30-day mortality but no difference in 60-day mortality. Multiple bowel resections were associated with an increased risk of postoperative AL, while no association was observed with body mass index (BMI), American Society of Anesthesiologists (ASA) score, age, smoking, operative approach (primary versus interval cytoreductive, stapled versus hand-sewn anastomoses and formation of diverting stoma), neoadjuvant chemotherapy and use of hyperthermic intraperitoneal chemotherapy (HIPEC). Discussion: Multiple bowel resections were the only clinical risk factor associated with increased risk for AL after bowel surgery in the ovarian cancer population. The increased 30-day mortality rate in patients undergoing ovarian cytoreduction complicated by AL highlights the need to minimize the number of bowel resections in this population. Further studies are required to clarify any association between neoadjuvant chemotherapy and decreased AL rates

Interfacial instability of density-stratified two-layer systems under initial stress

of interfacial instability in two coherent semi-infinite layers of different properties and the corresponding critical wavelength are found by solving a static bifurcation problem in finite plane strain. Subsequently, the stability of perturbations of any wavelength is determined from the appropriate linearized equations of motion. For gravitationally stable or unstable density stratifications, the critical stress at which the interface is destabilized is shown to depend on the wavelength of a perturbation ; it is also determined in a complex manner by initial stress gradients perpendicular to the layer interface and by layer stiffness, as is illustrated here in detail for the examples of a hyperelastic solid and an elastoplastic solid, both resting on an inviscid fluid of different density. The very large wavelength that is predicted for the gravitational instability of a semi-infinite elastic solid on a buoyant fluid substratum brings forward the essential role of pre-stress and associated stiffness reduction as well as that of a finite layer thickness in destabilizing geological and geophysical two-layer systems.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31051/1/0000728.pd

On the self-pinning character of synchro-Shockley dislocations in a Laves phase during strain rate cyclical compressions

Strain rate cyclical tests in compression, between 1350 and 1500 degrees C, have been employed to study the self-pinning character of thermally activated synchro-Shockley dislocations in the C15 Cr2Nb Laves phase. An average minimum effective (pinning) stress was calculated to be necessary for their propagation. The dislocation velocity cannot respond instantly to the strain rate changes and requires variations in the mobile dislocation density because the synchro-Shockleys can be pinned if the cooperating motion of their two Shockley components is hindered. (c) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

Sarcopenia is associated with a greater risk of polypharmacy and number of medications: a systematic review and meta-analysis

Polypharmacy in older adults is associated with multiple negative consequences that may affect muscular function, independently from the presence of medical conditions. The aim of this systematic review and meta-analysis was to investigate the association of sarcopenia with polypharmacy and higher number of medications. A systematic literature search of observational studies using PubMed, Web of Science, Scopus and Cochrane Library databases was conducted from inception until June 2022. To determine if sarcopenia is associated with a higher risk of polypharmacy and increased number of medications, a meta-analysis using a random-effects model was used to calculate the pooled effects (CRD42022337539). Twenty-nine studies were included in the systematic review and meta-analysis. Sarcopenia was associated with a higher prevalence of polypharmacy (odds ratio [OR]: 1.65, 95% confidence interval [CI] [1.23, 2.20], I2 = 84%, P < 0.01) and higher number of medications (mean difference: 1.39, 95% CI [0.59, 2.19], I2 = 95%, P < 0.01) compared with individuals without sarcopenia. Using meta-regression, a high variance was observed due to different populations (i.e., community-dwelling, nursing home residents, inpatients, outpatients) for both outcomes of polypharmacy (r = −0.338, SE = 0.1669, 95% CI [−0.67, −0.01], z = −2.03, P = 0.04) and number of medications (r = 0.589, SE = 0.2615, 95% CI [0.08, 1.10], z = 2.25, P = 0.02). This systematic review and meta-analysis reported a significantly increased risk of polypharmacy and higher number of medications in people with sarcopenia compared with individuals without this condition. Future research should clarify whether the specificity and number of medications is a direct contributor in accelerating the progression of muscle wasting and dysfunction contributing to sarcopenia in older adults

The mechanical properties and the deformation microstructures of the C15 Laves phase Cr2Nb at high temperatures

Compression tests between 1250 and 1550 degrees C and 10(-5) and 5 x 10(-3) s(-1) and transmission electron microscopy have been employed to investigate the high temperature mechanical properties and the deformation mechanisms of the C15 Cr2Nb Laves phase. The stress-peaks in the compression curves during yielding were explained using a mechanism similar to strain aging combined with a low initial density of mobile dislocations. The primary deformation mechanism is slip by extended dislocations with Burgers vector 1/2 <110 >, whereas twinning is more frequent at 10(-4) s(-1). Schmid factor analysis indicated that twinning is more probable in grains oriented so as to have two co-planar twinning systems with high and comparable resolved shear stresses. Twinning produced very anisotropic microstructures. This may be due to synchroshear: a self-pinning mechanism which requires co-operative motion of zonal dislocations. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

Onset of entanglement

We have developed a theory of polymer entanglement using an extended Cahn-Hilliard functional, with two extra terms. One is a nonlocal attractive term, operating over mesoscales, which is interpreted as giving rise to entanglement, and the other a local repulsive term indicative of excluded volume interactions. We show how such a functional can be derived using notions from gauge theory. We go beyond the Gaussian approximation, to the one-loop level, to show that the system exhibits a crossover to a state of entanglement as the average chain length between points of entanglement decreases. This crossover is marked by critical slowing down, as the effective diffusion constant goes to zero. We have also computed the tensile modulus of the system, and we find a corresponding crossover to a regime of high modulus.Comment: 18 pages, with 4 figure

Medium-chain triglycerides may improve memory in non-demented older adults: a systematic review of randomized controlled trials

publishedVersio

Medium-chain triglycerides may improve memory in non-demented older adults: a systematic review of randomized controlled trials

Background: Ketosis has been exploited for its neuroprotective impact and treatment of neurological conditions via ketone production. Exogenous medium-chain triglyceride (MCT) supplementation may induce nutritional ketosis. The aim of this systematic review is to explore the effects of MCTs on memory function in older adults without cognitive impairment. Methods: A systematic literature search of PubMed, Cochrane Library, Scopus, and Web of Science was employed from inception until April 2022 for randomized controlled trials (RCTs) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, investigating the impact of MCT oils on components of memory. Risk of bias (RoB2) tool was utilized for quality assessment. Results: Six trials were included for qualitative synthesis, in which two studies examined the effect of MCTs through a ketogenic meal. MCT supplementation compared to controls was associated with improved indices of memory function in 4 out of 6 studies, particularly working memory. A meta-analysis was not employed due to the low number of studies, therefore, a true effect measure of MCT supplementation was not explored. Conclusions: MCT supplementation may enhance working memory in non-demented older adults. These effects may be more prominent in individuals with lower baseline scores, from short and long-term supplementation. Further studies are warranted to confirm these findings in terms of optimal dose and MCTs composition, which may protect from memory decline during aging