Sensing of Oxygen Concentration in a Microfluidic Device mimicking Liver 3D Microarchitecture

International audienceWe designed a microfluidic structure which closely reproduces liver microarchitecture, constraining primary rat hepatocytes at a high density and in three dimensions (3D), and in which a gradient of oxygen can be generated. The device includes an oxygen sensitive membrane that could map the oxygen consumption of hepatocytes. INTRODUCTION Compared to classical two-dimensional cell culture, microfluidic devices or/and 3D culture conditions were evidenced to increase the period of time during which primary hepatocytes retain their functions [1]. Moreover, microfluidic techniques offer the opportunity to mimic the in vivo hepatocyte zonation, by subjecting hepatocytes to oxygen gradients [1-2]. Such oxygen gradients that can be estimated by numerical simulations, were recently experimentally assessed using an oxygen sensitive fluorescent membrane [3]. We proposed to include the oxygen sensitive membrane within a miniaturized fluidic device mimicking several hepatic cords in series, and inducing a gradient of oxygen on those. Moreover each of those hepatic cord units was inducing 3D organization of hepatocytes, due to the 72 µm height of culture chambers in which they can aggregate

Optical Measurements of High-Density Helicon Plasma by Using a High-Speed Camera and Monochromators * )

Electric propulsion is an established high-efficiency method in deep space explorers. However, most of the applied methods feature electrodes in direct contact with the plasma, thus its lifetime is limited by the electrodes' erosion. We developed electrodeless electric propulsion systems in order to overcome this problem, and performed optical measurements to estimate the high-density helicon plasma performance of the systems. The electron and neutral particle density profiles were measured by a high-speed camera, and the velocity of the singly-charged Ar ions was determined by a high-resolution monochromator. Additionally, a preliminary experiment of a spectroscopic method using an intensity ratio based on a collisional radiative model with a CCD monochromator was performed. The plasma parameters were in good agreement with the results obtained by an electrostatic probe, and the non-invasive optical measurements presented here can constitute an effective tool for evaluating an electric propulsion system

The bioprinting roadmap

This bioprinting roadmap features salient advances in selected applications of the technique and highlights the status of current developments and challenges, as well as envisioned advances in science and technology, to address the challenges to the young and evolving technique. The topics covered in this roadmap encompass the broad spectrum of bioprinting; from cell expansion and novel bioink development to cell/stem cell printing, from organoid-based tissue organization to bioprinting of human-scale tissue structures, and from building cell/tissue/organ-on-a-chip to biomanufacturing of multicellular engineered living systems. The emerging application of printing-in-space and an overview of bioprinting technologies are also included in this roadmap. Due to the rapid pace of methodological advancements in bioprinting techniques and wide-ranging applications, the direction in which the field should advance is not immediately clear. This bioprinting roadmap addresses this unmet need by providing a comprehensive summary and recommendations useful to experienced researchers and newcomers to the field

Reactive halogens (BrO and OClO) detected in the plume of Soufrière Hills Volcano during an eruption hiatus

Volcanic plumes are sites of dynamic chemistry involving halogen gases. Here we present new data on the relative abundances of SO2, BrO and OClO gases emitted from Soufrière Hills Volcano [SHV). They were collected during an eruptive hiatus but during sustained degassing at this halogen-rich volcano. By comparison with data from a previous study during an eruptive phase and application of the data and modeling of Villemant et al. (2008), we suggest that, after consideration of errors, either the rate of HBr conversion to BrO is variable, ranging from ∼30% to ∼15%, and/or the relative partitioning of Cl and Br into the gas phase from the melt changes according to eruptive activity. We examine the potential implications of this for fluid-melt partitioning, and compare our results with data from the experimental literature. Our work contributes toward understanding the controls on the BrO/SO2 ratio for volcano monitoring purposes; the changes in plume chemistry with regard to bromine at the onset of lava extrusion may be large and rapid. OClO was detected in the plume at SHV for the first time. This species has only previously been detected in emissions from Mount Etna (using ground-based methods) and from Puyehue Cordon Caulle (using satellite-based methods). No HCHO or NOy species were detected in the spectra.The MVO is thanked for support during fieldwork. This work was also supported by the UK National Centre for Earth Observation (“Dynamic Earth and Geohazards"; http://comet.nerc.ac.uk).This is the final published version. It's also available from Wiley at http://onlinelibrary.wiley.com/doi/10.1002/2014GC005419/abstract

Multicenter, single-blind, randomized controlled study of the efficacy and safety of favipiravir and nafamostat mesilate in patients with COVID-19 pneumonia

Objectives: To evaluate the efficacy and safety of nafamostat combined with favipiravir for the treatment of COVID-19. Methods: We conducted a multicenter, randomized, single-blind, placebo-controlled, parallel assignment study in hospitalized patients with mild-to-moderate COVID-19 pneumonia. Patients were randomly assigned to receive favipiravir alone (n = 24) or nafamostat with favipiravir (n = 21). The outcomes included changes in the World Health Organization clinical progression scale score, time to improvement in body temperature, and improvement in oxygen saturation (SpO2). Results: There was no significant difference in the changes in the clinical progression scale between nafamostat with favipiravir and favipiravir alone groups (median, -0.444 vs -0.150, respectively; least-squares mean difference, -0.294; P = 0.364). The time to improvement in body temperature was significantly shorter in the combination group (5.0 days; 95% confidence interval, 4.0-7.0) than in the favipiravir group (9.0 days; 95% confidence interval, 7.0-18.0; P =0.009). The changes in SpO2 were greater in the combination group than in the favipiravir group (0.526% vs -1.304%, respectively; least-squares mean difference, 1.831; P = 0.022). No serious adverse events or deaths were reported, but phlebitis occurred in 57.1% of the patients in the combination group. Conclusion: Although our study showed no differences in clinical progression, earlier defervescence, and recovery of SpO2 were observed in the combination group

Potential of Resveratrol Analogues as Antagonists of Osteoclasts and Promoters of Osteoblasts

The plant phytoalexin resveratrol was previously demonstrated to inhibit the differentiation and bone resorbing activity of osteoclasts, to promote the formation of osteoblasts from mesenchymal precursors in cultures, and inhibit myeloma cell proliferation, when used at high concentrations. In the current study, we screened five structurally modified resveratrol analogues for their ability to modify the differentiation of osteoclasts and osteoblasts and proliferation of myeloma cells. Compared to resveratrol, analogues showed an up to 5,000-fold increased potency to inhibit osteoclast differentiation. To a lesser extent, resveratrol analogues also promoted osteoblast maturation. However, they did not antagonize the proliferation of myeloma cells. The potency of the best-performing candidate in vitro was tested in vivo in an ovariectomy-induced model of osteoporosis, but an effect on bone loss could not be detected. Based on their powerful antiresorptive activity in vitro, resveratrol analogues might be attractive modulators of bone remodeling. However, further studies are required to establish their efficacy in vivo

The Brain Tumor Segmentation (BraTS) Challenge 2023: Brain MR Image Synthesis for Tumor Segmentation (BraSyn)

Automated brain tumor segmentation methods have become well-established and reached performance levels offering clear clinical utility. These methods typically rely on four input magnetic resonance imaging (MRI) modalities: T1-weighted images with and without contrast enhancement, T2-weighted images, and FLAIR images. However, some sequences are often missing in clinical practice due to time constraints or image artifacts, such as patient motion. Consequently, the ability to substitute missing modalities and gain segmentation performance is highly desirable and necessary for the broader adoption of these algorithms in the clinical routine. In this work, we present the establishment of the Brain MR Image Synthesis Benchmark (BraSyn) in conjunction with the Medical Image Computing and Computer-Assisted Intervention (MICCAI) 2023. The primary objective of this challenge is to evaluate image synthesis methods that can realistically generate missing MRI modalities when multiple available images are provided. The ultimate aim is to facilitate automated brain tumor segmentation pipelines. The image dataset used in the benchmark is diverse and multi-modal, created through collaboration with various hospitals and research institutions.Comment: Technical report of BraSy

The Brain Tumor Segmentation (BraTS) Challenge 2023: Focus on Pediatrics (CBTN-CONNECT-DIPGR-ASNR-MICCAI BraTS-PEDs)

Pediatric tumors of the central nervous system are the most common cause of cancer-related death in children. The five-year survival rate for high-grade gliomas in children is less than 20\%. Due to their rarity, the diagnosis of these entities is often delayed, their treatment is mainly based on historic treatment concepts, and clinical trials require multi-institutional collaborations. The MICCAI Brain Tumor Segmentation (BraTS) Challenge is a landmark community benchmark event with a successful history of 12 years of resource creation for the segmentation and analysis of adult glioma. Here we present the CBTN-CONNECT-DIPGR-ASNR-MICCAI BraTS-PEDs 2023 challenge, which represents the first BraTS challenge focused on pediatric brain tumors with data acquired across multiple international consortia dedicated to pediatric neuro-oncology and clinical trials. The BraTS-PEDs 2023 challenge focuses on benchmarking the development of volumentric segmentation algorithms for pediatric brain glioma through standardized quantitative performance evaluation metrics utilized across the BraTS 2023 cluster of challenges. Models gaining knowledge from the BraTS-PEDs multi-parametric structural MRI (mpMRI) training data will be evaluated on separate validation and unseen test mpMRI dataof high-grade pediatric glioma. The CBTN-CONNECT-DIPGR-ASNR-MICCAI BraTS-PEDs 2023 challenge brings together clinicians and AI/imaging scientists to lead to faster development of automated segmentation techniques that could benefit clinical trials, and ultimately the care of children with brain tumors

Islet Endothelial Activation and Oxidative Stress Gene Expression Is Reduced by IL-1Ra Treatment in the Type 2 Diabetic GK Rat

Inflammation followed by fibrosis is a component of islet dysfunction in both rodent and human type 2 diabetes. Because islet inflammation may originate from endothelial cells, we assessed the expression of selected genes involved in endothelial cell activation in islets from a spontaneous model of type 2 diabetes, the Goto-Kakizaki (GK) rat. We also examined islet endotheliuml/oxidative stress (OS)/inflammation-related gene expression, islet vascularization and fibrosis after treatment with the interleukin-1 (IL-1) receptor antagonist (IL-1Ra)