Droplet Coalescence and Freezing on Hydrophilic, Hydrophobic, and Biphilic Surfaces

Frost and ice formation can have severe negative consequences, such as aircraft safety and reliability. At atmospheric pressure, water heterogeneously condenses and then freezes at low temperatures. To alter this freezing process, this research examines the effects of biphilic surfaces (surfaces which combine hydrophilic and hydrophobic regions) on heterogeneous water nucleation, growth, and freezing. Silicon wafers were coated with a self-assembled monolayer and patterned to create biphilic surfaces. Samples were placed on a freezing stage in an environmental chamber at atmospheric pressure, at a temperature of 295 K, and relative humidities of 30%, 60%, and 75%. Biphilic surfaces had a significant effect on droplet dynamics and freezing behavior. The addition of biphilic patterns decreased the temperature required for freezing by 6 K. Biphilic surfaces also changed the size and number of droplets on a surface at freezing and delayed the time required for a surface to freeze. The main mechanism affecting freezing characteristics was the coalescence behavior.Citation: A. Van Dyke, D. Collard, M. M. Derby and A. R. Betz, "Droplet Coalescence and Freezing on Hydrophilic, Hydrophobic, and Biphilic Surfaces," Applied Physics Letters, 107, Issue 14, 201

Learning together for and with the Martuwarra Fitzroy River

Co-production across scientific and Indigenous knowledge systems has become a cornerstone of research to enhance knowledge, practice, ethics, and foster sustainability transformations. However, the profound differences in world views and the complex and contested histories of nation-state colonisation on Indigenous territories, highlight both opportunities and risks for Indigenous people when engaging with knowledge co-production. This paper investigates the conditions under which knowledge co-production can lead to improved Indigenous adaptive environmental planning and management among remote land-attached Indigenous peoples through a case study with ten Traditional Owner groups in the Martuwarra (Fitzroy River) Catchment in Western Australia’s Kimberley region. The research team built a 3D map of the river and used it, together with an interactive table-top projector, to bring together both scientific and Indigenous spatial knowledge. Participatory influence mapping, aligned with Traditional Owner priorities to achieve cultural governance and management planning goals set out in the Fitzroy River Declaration, investigated power relations. An analytical framework, examining underlying mechanisms of social learning, knowledge promotion and enhancing influence, based on different theories of change, was applied to unpack the immediate outcomes from these activities. The analysis identified that knowledge co-production activities improved the accessibility of the knowledge, the experiences of the knowledge users, strengthened collective identity and partnerships, and strengthened Indigenous-led institutions. The focus on cultural governance and management planning goals in the Fitzroy River Declaration enabled the activities to directly affect key drivers of Indigenous adaptive environmental planning and management—the Indigenous-led institutions. The nation-state arrangements also gave some support to local learning and decision-making through a key Indigenous institution, Martuwarra Fitzroy River Council. Knowledge co-production with remote land-attached Indigenous peoples can improve adaptive environmental planning and management where it fosters learning together, is grounded in the Indigenous-led institutions and addresses their priorities

Wild-type and mutant SOD1 share an aberrant conformation and a common pathogenic pathway in ALS.

Many mutations confer one or more toxic function(s) on copper/zinc superoxide dismutase 1 (SOD1) that impair motor neuron viability and cause familial amyotrophic lateral sclerosis (FALS). Using a conformation-specific antibody that detects misfolded SOD1 (C4F6), we found that oxidized wild-type SOD1 and mutant SOD1 share a conformational epitope that is not present in normal wild-type SOD1. In a subset of human sporadic ALS (SALS) cases, motor neurons in the lumbosacral spinal cord were markedly C4F6 immunoreactive, indicating that an aberrant wild-type SOD1 species was present. Recombinant, oxidized wild-type SOD1 and wild-type SOD1 immunopurified from SALS tissues inhibited kinesin-based fast axonal transport in a manner similar to that of FALS-linked mutant SOD1. Our findings suggest that wild-type SOD1 can be pathogenic in SALS and identify an SOD1-dependent pathogenic mechanism common to FALS and SALS

Enhancing Solid Propellants with Additively Manufactured Reactive Components and Modified Aluminum Particles

A variety of methods have been developed to enhance solid propellant burning rates, including adjusting oxidizer particle size, modifying metal additives, tailoring the propellant core geometry, and adding catalysts or wires. Fully consumable reactive wires embedded in propellant have been used to increase the burning rate by increasing the surface area; however, the manufacture of propellant grains and the observation of geometric effects with reactive components has been restricted by traditional manufacturing and viewing methods. In this work, a printable reactive filament was developed that is tailorable to a number of use cases spanning reactive fibers to photosensitive igniters. The filament employs aluminum fuel within a printable polyvinylidene fluoride matrix that can be tailored to a desired burning rate through stoichiometry or aluminum fuel configuration such as particle size and modified aluminum composites. The material is printable with fused filament fabrication, enabling access to more complex geometries such as spirals and branches that are inaccessible to traditionally cast reactive materials. However, additively manufacturing the reactive fluoropolymer and propellant together comes attendant with many challenges given the significantly different physical properties, particularly regarding adhesion. To circumvent the challenges posed by multiple printing techniques required for such dissimilar materials, the reactive fluoropolymer was included within a solid propellant carrier matrix as small fibers. The fibers were varied in aspect ratio (AR) and orientation, with aspect ratios greater than one exhibiting a self-alignment behavior in concordance with the prescribed extrusion direction. The effective burning rate of the propellant was improved nearly twofold with 10 wt.% reactive fibers with an AR of 7 and vertical orientation. The reactive wires and fibers in propellant proved difficult to image in realistic sample designs, given that traditional visible imaging techniques restrict the location and dimensions of the reactive wire due to the necessity of an intrusive window next to the wire, a single-view dynamic X-ray imaging technique was employed to analyze the evolution of the internal burning profile of propellant cast with embedded additively manufacture reactive components. To image complex branching geometries and propellant with multiple reactive components stacked within the same line of sight, the dynamic X-ray imaging technique was expanded to two views. Topographic reconstructions of propellants with multiple reactive fibers showed the evolution of the burning surface enhanced by the geometric effects caused by the faster burning fibers. These dual-view reconstructions provide a method for accurate quantitative analysis of volumetric burning rates that can improve the accessibility and viability of novel propellant grain designs

The endogenous cannabinoid, anandamide, induces COX-2-dependent cell death in apoptosis-resistant colon cancer cells

Despite recent advances in understanding colorectal tumour biology, there is still a need to improve the 5-year survival rate of patients with colorectal cancer as approximately 40% of patients presenting with advanced disease will remain resistant to therapy. One of the major contributing factors in resistance to therapy is the failure of colorectal tumour cells to undergo apoptosis. Hence there is an urgent need to develop novel therapeutic approaches that can target apoptosis-resistant cells. To this end, we investigated the potential efficacy of the endogenous cannabinoid anandamide to induce cell death in apoptosis-resistant colon cancer cells. Here, for the first time, we show that anandamide can induce cell death in the apoptosis-resistant HCT116 Bax−/− colorectal cell line. Importantly, we provide direct genetic evidence that this induction of cell death is dependent on COX-2 expression. Interestingly, increased COX-2 expression also sensitised the SW480 colorectal cancer cell line (low endogenous COX-2) to anandamide-induced death, whereas COX-2 suppression by RNAi inhibited anandamide-induced cell death in the HCA7 colorectal cancer cell line (high endogenous COX-2 expression). This COX-2-dependent death was independent of cannabinoid receptor engagement (CB1 or CB2), and not a direct consequence of reactive oxygen species (ROS) formation. This study demonstrates a novel utilisation for COX-2 expression, targeting apoptotic defective colorectal cancer cells for destruction by anandamide. As COX-2 is not expressed in the normal colorectal epithelium, but highly expressed in colorectal tumours and apoptosis resistance contributes to treatment failure, these data suggest that anandamide has the potential to be an effective therapeutic in colorectal cancer

Re: Re: ``Adult appendicitis: Clinical practice guidelines from the French Society of Digestive Surgery (SFCD) and the Society of Abdominal and Digestive Imaging (SIAD)

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Éducation technologique et sciences de l’ingénieur

Le renouvellement de la technologie dans les enseignements est perceptible dans l'étiquetage diversifié de l'offre de cours (« technologie », « technologies », « technosciences », « sciences de l'ingénieur », « sciences industrielles de l’ingénieur », « sciences et technologies de l’ingénieur », etc.). Il s’accompagne de la révision des contenus qui tient compte des mutations des pratiques sociotechniques contemporaines, de la volonté de faire de l’éducation technologique une composante de la formation générale, mais aussi des rapports avec les enseignements scientifiques (intégration des sciences et de la technologie, référence aux technosciences). Les contenus sont également renouvelés par la prise en considération des nouveaux enjeux associés aux problématiques sociétales telles que le développement durable. Tout en faisant le point sur les problématiques didactiques associées à ces changements et en contribuant au renouvellement des réflexions sur l’enseignement et l’apprentissage de la technologie, cette approche franco-québécoise vise à proposer des perspectives de recherche et d’expertise didactiques futures.This bookgathers contributions from France and Quebec. It presents contemporary educational issues linked with deep renewal of technology education from primary school to university, within general or technological and vocational education

Nonmetastatic ypt0 rectal cancer after neoadjuvant treatment and total mesorectal excision: Lessons from a retrospective multicentric cohort of 383 patients

International audienc

Iatrogenic ureteral injury during colorectal surgery has a significant impact on patient outcomes: a French multicentric retrospective cohort study

International audienceAim: The long-term urological sequelae after iatrogenic ureteral injury (IUI) during colorectal surgery are not clearly known. The aims of this work were to report the incidence of IUI and to analyse the long-term consequences of urological late complications and their impact on oncological results of IUI occurring during colorectal surgery through a French multicentric experience (GRECCAR group).Method: All the patients who presented with IUI during colorectal surgery between 2010 and 2019 were retrospectively included. Patients with ureteral involvement needing en bloc resection, delayed ureteral stricture or noncolorectal surgery were not considered.Results: A total of 202 patients (93 men, mean age 63 ± 14 years) were identified in 29 centres, corresponding to 0.32% of colorectal surgeries (n = 63 562). Index colorectal surgery was mainly oncological (n = 130, 64%). IUI was diagnosed postoperatively in 112 patients (55%) after a mean delay of 11 ± 9 days. Intraoperative diagnosis of IUI was significantly associated with shorter length of stay (21 ± 22 days vs. 34 ± 22 days, p < 0.0001), lower rates of postoperative hydronephrosis (2% vs. 10%, p = 0.04), anastomotic complication (7% vs. 22.5%, p = 0.002) and thromboembolic event (0% vs. 6%, p = 0.02) than postoperative diagnosis of IUI. Delayed chemotherapy because of IUI was reported in 27% of patients. At the end of the follow-up [3 ± 2.6 years (1 month-13 years)], 72 patients presented with urological sequalae (36%). Six patients (3%) required a nephrectomy.Conclusion: IUI during colorectal surgery has few consequences for the patients if recognized early. Long-term urological sequelae can occur in a third of patients. IUI may affect oncological outcomes in colorectal surgery by delaying adjuvant chemotherapy, especially when the ureteral injury is not diagnosed peroperatively