263134 research outputs found
Sort by
Point-of-care visco-elastic testing for postpartum haemorrhage
No full textPostpartum haemorrhage (PPH) remains a leading cause of maternal morbidity and mortality worldwide. While coagulation disorders are seldom the primary cause of PPH and are rare early in PPH, the incidence of coagulation abnormalities increases when blood loss escalates. Acute obstetric coagulopathy (AOC), with an incidence of one in 1000 deliveries, has emerged as a distinct coagulopathy in PPH, highlighting the need for timely coagulation testing and intervention. This narrative review examines the current evidence on the use of visco-elastic haemostatic assays (VHAs) to guide treatment in PPH, and further explores the prophylactic and therapeutic roles of fibrinogen and tranexamic acid (TXA). VHAs have shown potential in PPH management, with large prospective and retrospective cohort studies demonstrating reductions in transfusions and transfusion-related complications. However, these findings have not been consistently replicated, possibly due to variations in study design and statistical power. This review explores the benefits and limitations of VHAs in the context of PPH management. Until large, well designed studies suggest otherwise, women with PPH might benefit from access to VHAs, given their potential to improve clinical outcomes in large cohorts without evidence of associated harm. Fibrinogen replacement is essential in PPH management. VHAs have been shown to be as effective as the Clauss fibrinogen assay in guiding fibrinogen substitution during PPH. Recent updates to ROTEM Sigma cartridges have led to new FIBTEM A5 thresholds, with the Obstetric Bleeding Strategy (OBS) group of Wales proposing a FIBTEM A5 of 8 mm or less as the new trigger for fibrinogen replacement in PPH. Fibrinogen concentrate offers advantages over cryoprecipitate and may be preferred when both are available. Effective fibrinogen substitution not only corrects VHA results but also helps to control bleeding. TXA is a cornerstone in the treatment of PPH and should be administered promptly at a dose of 1 g as soon as PPH is diagnosed, regardless of VHA results, and always within three hours of onset. A second dose may be given if bleeding persists or recurs. However, high-quality randomised trials have consistently shown no benefit from prophylactic TXA in low-risk caesarean section or in vaginal births across all risk groups. Data on the prophylactic use of TXA in high-risk caesarean section are limited and its use in these cases should be based on clinical judgement and individual risk assessment.status: Accepte
Mealtime Physiological Responses in Individuals With Eating Disorders and Healthy Controls
No full textOBJECTIVE: Mealtimes are highly distressing for individuals with eating disorders (ED), potentially reinforcing disordered eating and complicating recovery. Yet, physiological responses during meals remain understudied. This study explores autonomic nervous system responses during meals in individuals with ED and healthy controls (HC). METHODS: Three studies assessed heart rate (HR), heart rate variability (HRV), skin conductance response (SCR), and skin temperature (ST) around lunchtime. Study 1 included 47 hospitalized adult women with ED (26 anorexia nervosa (AN), 8 atypical AN, 13 bulimia nervosa (BN)). Studies 2 and 3 involved 47 and 58 HC in daily life. RESULTS: Patients reported elevated subjective stress but showed no expected physiological responses in HR. Instead, HR decreased during meals for all patients and increased after in those with BN. No significant changes were observed in HRV or SCR. No ST changes were observed in AN, while BN showed the expected pre-lunch decrease and post-lunch increase. In HC, HR and SCR rose pre-meal, HRV decreased, and ST increased during meals. DISCUSSION: These findings suggest a mismatch between subjective and physiological stress in ED. Chronic stress or undernutrition may alter autonomic reactivity, although not directly assessed. Future research should investigate how these factors shape physiological stress responses.sponsorship: The authors have informed the journal that they agree that both Emma De Schuyteneer and Robin Quagebeur completed the intellectual and other work typical of the first author. (Delport & De Beys King Baudouin Foundation)status: Published onlin
Unique and Interactive Associations between Maternal and Paternal Attachment Predicting Depressive Symptoms in Iranian Female Adolescents
No full textstatus: Accepte
Data Protection Without Romance: The Power Asymmetries that the GDPR Does Counter
No full textA clear and consensual conceptualization of the power asymmetries that data protection seeks to address is missing. That modern bigness translates into multifaceted power issues results in multiple branches of the law being increasingly called upon to respond, illustrated by the recent adoption of the EU digital package. Such an endeavor requires consistency between them and thus also a clear vision of which legal framework addresses which power issue(s) and how. To spin a musical metaphor, for the choir to be harmonious requires that every singer sings their own score. This article unpacks the nature and ways in which data protection addresses power asymmetries through ‘data control’. It does it through an enquiry into the conceptual relationship between ‘data’ and ‘control’ or power under data protection.status: Publishe
Anisotropic mechanical characterization of trabecular bone with linear and non-linear voxel-based finite elements from photon-counting CT
No full textBone structural and mechanical properties predict fragility fractures, but unexplained variance remains. A better quantification of the anisotropic nature of bone, and an improved model-based prediction of bone failure load could fill in this gap. Yet, quantifying mechanical anisotropy requires high-resolution imaging modalities, which are often lacking in clinical practice. This study used voxel-based finite element (FE) models from high-resolution photon-counting CT (PCCT) and conventional energy-integrating detector CT (EIDCT) to mechanically characterize trabecular bone samples from vertebrae. Ten trabecular cubical samples from bovine lumbar vertebrae were scanned with PCCT, EIDCT and micro-CT (μCT), calibrated to bone mineral density values, and images were converted to voxel-based FE meshes. A density-scaled linear-elastic material model was employed to calculate the apparent stiffness tensor in the orthotropic direction, and results from PCCT and EIDCT were compared to μCT-based reference values. Anisotropy of the resulting linear-elastic material parameters was quantified as the ratio of axial to transverse moduli. Next, a non-linear density-scaled material model that included a plastic and strain-softening phase was used to quantify failure load. Anisotropy of failure load in the orthotropic directions was compared between PCCT and EIDCT, and axial failure load was compared to experimental measurements. For PCCT, all apparent Young's and shear moduli showed no systematic bias with respect to μCT; in contrast, EIDCT systematically overestimated all transverse moduli, and underestimated the axial Young's modulus. As a result, the anisotropic nature of bone was better quantified with PCCT (1.71 ± 0.28) than with EIDCT (1.22 ± 0.14). Similarly, PCCT demonstrated higher anisotropy of failure loads in the orthotropic directions (1.75 ± 0.27) than EIDCT did (1.28 ± 0.17). Compared to experimental measurements, all voxel-based FE models underestimated failure load, yet, adjusted R2 was higher for PCCT (0.91) than for EIDCT (0.84). For multivariate linear models that incorporated both FE failure load and trabecular bone microarchitecture, adjusted R2 increased to 0.98 for PCCT, and 0.91 for EIDCT. We conclude that the increased resolution of PCCT enables a better linear-elastic characterization as compared to EIDCT, and that PCCT is more predictive of failure load than EIDCT. This could aid in clinically relevant fracture risk predictions.sponsorship: This project has received funding from the FWO and F.R.S.-FNRS under the Excellence of Science (EOS) program (EOS No. 40007553) and from the KU Leuven Industrial Research Fund (IOF) for project C24E/21/030. (FWO, F.R.S.-FNRS under the Excellence of Science (EOS) program (EOS)|40007553, KU Leuven Industrial Research Fund (IOF)|C24E/21/030)status: Accepte
Local recurrence after glans-sparing surgery: no impact on penile cancer-specific survival
No full textOBJECTIVES: To assess local recurrence (LR) and its impact on cancer-specific survival (CSS) in an international multicentric homogeneous cohort of lower-risk patients with penile squamous cell carcinoma (PSCC) that underwent glans-sparing surgery (GSS). PATIENTS AND METHODS: We retrospectively studied patients with PSCC treated with circumcision, wide local excision, glans resurfacing, partial glansectomy and laser ablation, collectively defined as GSS. To understand whether LR itself impacts CSS, patients with lymphatic or systemic disease prior or concurrent with LR were excluded. Predictors of LR and its impact on CSS were assessed using Cox proportional hazard regression and Kaplan-Meier survival analysis, respectively. RESULTS: Across 15 institutions, 550 patients were included. The majority had pathological T1 stage (79%) tumours, reflecting the selection of less invasive tumours for GSS. At a median (interquartile range) follow-up of 41 (23-63) months, 162 (29%) patients experienced LR. LR did not affect cancer-specific mortality and 5-year CSS remained at 99%. Three patients died from penile cancer, none of whom showed a LR during their disease course. The presence of penile intraepithelial neoplasia in the surgical margin was an independent predictor of LR (hazard ratio 2.28, P = 0.02), even after adjusting for additional treatments. CONCLUSION: Patients undergoing GSS for PSCC demonstrate excellent survival outcomes, despite LR in 29% of men. These findings support the use of GSS as a safe and effective treatment option for patients committed to adequate follow-up.status: Published onlin
Plant prebiotica: de rol van de fyllosfeer tijdens fructaan priming als verdediging tegen grauwe schimmel (Botrytis cinerea) in sla (Lactuca sativa)
No full textSome natural compounds are known to enhance the immune system of plants by a process called priming, which is comparable to the immune-stimulating properties of vaccines in humans. Fructose polymers termed fructans have recently been shown to act as priming agents protecting lettuce (Lactuca sativa) against grey mold (Botrytis cinerea) when sprayed onto the leaf surface, however their method of action remains unknown. Fructans may be recognized by plant receptors that trigger cellular signaling and ultimately the activation of defense responses. However, plant receptors able to recognize fructans are not yet identified. In humans, fructans act as prebiotics, meaning that they stimulate the growth of healthpromoting microorganisms in the gastrointestinal tract. We propose that fructans could act in a similar way in plants, shifting the balance of pathogenic and beneficial plant-associated microorganisms towards a more beneficial state, ultimately contributing to disease control. This second hypothesis will be the focus of this project and will be investigated through culture-dependent and -independent approaches after isolation of microorganisms living in the lettuce leaf environment (the so-called phyllosphere). Extending the prebiotic concept to horticulture and agriculture represents a novel strategy in sustainable plant protection.status: Publishe
Decision support system development for store flyer space allocation: Leveraging own- and cross-category sales effects
No full textsponsorship: We thank Kay Peters (University of Hamburg, Germany) , Anne ter Braak (KU Leuven, Belgium) , Michael Haenlein (ESCP Business School) and Bart Lariviere (KU Leuven, Belgium) for their feedback on earlier drafts of this manuscript. We are thankful to Luuk Veelenturf for guiding us towards the concept of destroy-than-repair heuristics. Moreover, we wish to acknowledge Paulo Rossini, the ERIM Research Data Steward, and Govert Buijs, Scientific Developer at RSM, for their valuable input in developing the OSF repository. We are also grateful for the funding that was received from KU Leuven, Belgium. The authors have no conflict of interest. (KU Leuven, Belgium)status: Publishe
Stromingsakoestische karakterisatie van microperforaties: een studie naar de invloed van aerodynamische druk en perforatiegeometrie
No full textConventional sound mitigation solutions for flow ducts typically utilize macro-perforated structures combined with fibrous or porous materials. While effective, these approaches have the drawback of leading to bulky designs for low-frequency attenuation in which the used materials are often flammable and prone to degradation. These limitations contrast with the growing demand for lightweight, compact, and environmentally friendly designs. Micro-perforated panels (MPPs) present a promising alternative. Consisting of thin plates perforated with numerous sub-millimeter holes, MPPs enhance visco-thermal attenuation by dissipating acoustic energy through viscous forces inside the sub-millimeter openings. This allows them to achieve high acoustic resistance without additional absorptive materials, enabling the development of more compact silencers with clean airflow.
In order to effectively integrate MPPs into sound mitigation designs, accurate prediction models are essential. These descriptions typically represent MPPs as boundary conditions in flow-acoustic propagation solvers, where the impedance of the perforations plays a critical role. While semi-empirical models accurately describe the impedance of circular perforations in the absence of flow, mass manufacturing techniques often produce irregular, non-circular geometries which influence the acoustic properties and must be accounted for. Moreover, the specific flow conditions are known to significantly impact the acoustic behavior of perforations. Although empirical models have been derived for macro-perforated geometries under different flow conditions, disagreement exists of which flow parameters are most suitable to characterize the acoustic impedance. Furthermore, even when the same flow parameter is used, there tend to be a large deviation on the empirically determined coefficients, making it challenging to scale these models towards sub-millimeter dimensions. The goal of this thesis is to evaluate the influence of the geometry and flow conditions on the acoustic performance of sub-millimeter perforations.
The first objective of this thesis focuses on developing and validating a suitable measurement framework to characterize the acoustic impedance of micro-perforations in the wall of a flow duct. To measure the relevant acoustic pressures and acoustic particle velocities constituting this variable, an indirect measurement approach is employed, combining a multi-microphone side-branch set-up with a three-port scattering matrix formulation. In addition, a correction step is implemented to account for plate dynamic effects and a side-branch fan is installed to control the aerodynamic pressure drop over the perforations.
The second objective uses the experimental methodology to identify the key flow-acoustic variables to describe sub-millimeter perforations in design guidelines. Reference measurements are conducted on well-defined circular perforations and are compared to commonly used empirical correlations and corrections from the literature. In pure grazing flow conditions, measurements for perforation diameters ranging from 0.5 to 3 mm demonstrate how models based on flow Mach number and skin friction velocity qualitatively predict the observed trends. However, the correlation coefficients derived for macro-perforations do not scale well to sub-millimeter dimensions, necessitating their re-evaluation. Furthermore, the influence of a non-zero aerodynamic pressure difference across the sub-millimeter perforations is assessed both with and without grazing flow. The results reveal a large sensitivity of the measured impedance to small pressure differences, emphasizing the need for precise characterization of this parameter.
The third objective explores the use of numerical simulations to predict the experimentally observed trends for sub-millimeter orifices in order to gain a deeper understanding of the underlying physical phenomena. Using a two-step calculation procedure, the perturbed linearized Navier-Stokes equations are solved under an isentropic assumption while neglecting turbulent damping. In quiescent conditions, simulations show excellent agreement with experimental results. However, under grazing flow, only qualitative agreement is observed, with quantitative discrepancies becoming larger at low Mach numbers and higher frequencies. These deviations suggest an underestimation of the viscous scrubbing losses, likely due to the absence of thermal effects and the inability to fully capture the local flow field around the perforations. For cases with an additional bias flow, simulations are restricted to 2D geometries, limiting their use for quantitative predictions, but still capturing the experimentally observed trends.
The final objective assesses the potential of the combined experimental-numerical methodology in characterizing the effects of perforation geometry by focusing on a single geometrical parameter: the perforation inclination angle. In the presence of grazing flow, the orientation of the inclination relative to the flow direction has a significant impact on the measured impedance, even for small inclination angles. Perforations inclined against the flow direction show a weaker dependence on frequency compared to those aligned with the flow direction. Using global flow variables such as the flow Mach number and aerodynamic pressure difference, numerical simulations qualitatively predict the trends observed for an orifice inclined in the flow direction. However, these variables prove insufficient in capturing the experimental trends when the perforations are inclined with the flow, where the impact of local flow phenomena on the perforation impedance appear to be more outspoken.status: Publishe
A questionable account of ethnographic validity: Sukuma dandies in Katavi, Tanzania
No full textsponsorship: VLIRUOS-IUC Mzumbe U, FWO G.A005.14N, G044223Nstatus: Publishe