A standing Leidenfrost drop with Sufi-whirling

The mobility of Leidenfrost drop has been exploited for the manipulation of drop motions. In the classical model, the Leidenfrost drop was levitated by a vapor cushion, in the absence of touch to the surface. Here we report a standing Leidenfrost state on a heated hydrophobic surface where drop stands on the surface with partial adhesion and further self-rotates like Sufi-whirling. To elucidate this new phenomenon, we imaged the evolution of the partial adhesion, the inner circulation, and the ellipsoidal rotation of the drop. The stable partial adhesion is accompanied by thermal and mechanical equilibrium, and further drives the development of the drop rotation.Comment: 16 pages, 4 figure

Flexible Riser Configuration Design for Extremely Shallow Water With Surrogate-Model- Based Optimization

The aim of this paper is to study the optimization design of a steep wave configuration based on a surrogate model for an extremely shallow water application of a flexible riser. As the traditional technique of riser configuration design is rather time-consuming and exhaustive due to the nonlinear time domain analysis and large quantities of load cases, it will be challenging when engineers address an extreme design, such as the configuration design in the case of extremely shallow water. To avoid expensive simulations, surrogate models are constructed in this paper with the Kriging model and radial basis function (RBF) networks by using the samples obtained by optimal Latin hypercubic sampling (LHS) and time domain analysis in a specified design space. The RBF model is found to be easier to construct and to show better accuracy compared with the Kriging model according to the numerical simulations in this work. On the basis of the RBF model, a hybrid optimization is performed to find the minimum curvature design with corresponding engineering constraints. In addition, an optimized design is found to meet all of the design criteria with high accuracy and efficiency, even though all of the samples associated with construction of the surrogate model fail to meet the curvature criterion. Thus, the technique developed in this paper provides a novel method for riser configuration design under extreme conditions

Reconstruction accuracy dependence with induced-shear-wave magnitude in Magnetic Resonance Elastography

Congrès sous l’égide de la Société Française de Génie Biologique et Médical (SFGBM)National audienceSince 1996, Magnetic Resonance Elastography (MRE) holds the promise for absolute quantitation of the mechanical parameters of living tissues [1]. The reproducibility of the technique was challenged [2] while the measurement precision was determined by the uncertainty of the recorded MR-signal phase onto which the inferred motion is encoded [3]. We assumed that the ratio of the resulting total wave amplitude to its related uncertainty, AT/ΔAT,_ _should be considered to validate the acquired set of MRE data. Nevertheless, as long as this ratio is greater than unity, the validity of the extracted mechanical parameters might not be questioned. Here, we extract the complex shear modulus, G=G′+G′′, by inversion of the three-dimensional equation of motion [4] for a wide range of inferred wave amplitude, starting from zero, in a breast phantom. The shear dynamic, G′, and loss, G′′, moduli were found to increase with the wave amplitude before reaching a plateau at ratios AT/ΔAT much greater than one. Experiments were carried with standard motion-sensitized refocused field echo (RFE) [1] and motion fractional-encoding fast field echo (FFE) [5], for which sensitivities largely differ, so the relevance of a MRE-validity threshold based on the ratio AT/ΔAT could be exhibited

Fc gamma receptor IIb in tumor-associated macrophages and dendritic cells drives poor prognosis of recurrent glioblastoma through immune-associated signaling pathways

Background: Among central nervous system tumors, glioblastoma (GBM) is considered to be the most destructive malignancy. Recurrence is one of the most fatal aspects of GBM. However, the driver molecules that trigger GBM recurrence are currently unclear.Methods: The mRNA expression data and clinical information of GBM and normal tissues were collected from the Chinese Glioma Genome Atlas The Cancer Genome Atlas (TCGA), and REpository for Molecular BRAin Neoplasia DaTa (REMBRANDT) cohorts. The DESeq2 R package was used to identify the differentially expressed genes between primary and recurrent GBM. ClueGO, Kyoto Encyclopedia of Genes and Genomes (KEGG), Biological Process in Gene ontology (GO-BP), and the Protein ANalysis THrough Evolutionary Relationships (PANTHER) pathway analyses were performed to explore the enriched signaling pathways in upregulated DEGs in recurrent GBM. A gene list that contained potential oncogenes that showed a significant negative correlation with patient survival from The Cancer Genome Atlas was used to further screen driver candidates for recurrent GBM. Univariate Cox proportional hazards regression analyses were used to investigate the risk score for the mRNA expression of the candidates. Single-cell RNA sequencing (scRNA-Seq) analyses were used to determine the cell type-specific distribution of Fc gamma receptor II b (FcγRIIb) in GBM. Immunohistochemistry (IHC) was used to confirm the FcγRIIb-positive cell populations in primary and paired recurrent GBM.Results: Through DEG analysis and overlap analysis, a total of 10 genes that are upregulated in recurrent GBM were screened. Using validation databases, FcγRIIb was identified from the 10 candidates that may serve as a driver for recurrent GBM. FCGR2B expression, not mutation, further showed a highly negative correlation with the poor prognosis of patients with recurrent GBM. Furthermore, scRNA-Seq analyses revealed that tumor-associated macrophage- and dendritic cell-specific FCGR2B was expressed. Moreover, FcγRIIb also showed a strong positive correlation coefficient with major immune-associated signaling pathways. In clinical specimens, FcγRIIb-positive cell populations were higher in recurrent GBM than in primary GBM.Conclusion: This study provides novel insights into the role of FcγRIIb in recurrent GBM and a promising strategy for treatment as an immune therapeutic target

Boosting with an aerosolized Ad5-nCoV elicited robust immune responses in inactivated COVID-19 vaccines recipients

IntroductionThe SARS-CoV-2 Omicron variant has become the dominant SARS-CoV-2 variant and exhibits immune escape to current COVID-19 vaccines, the further boosting strategies are required.MethodsWe have conducted a non-randomized, open-label and parallel-controlled phase 4 trial to evaluate the magnitude and longevity of immune responses to booster vaccination with intramuscular adenovirus vectored vaccine (Ad5-nCoV), aerosolized Ad5-nCoV, a recombinant protein subunit vaccine (ZF2001) or homologous inactivated vaccine (CoronaVac) in those who received two doses of inactivated COVID-19 vaccines. ResultsThe aerosolized Ad5-nCoV induced the most robust and long-lasting neutralizing activity against Omicron variant and IFNg T-cell response among all the boosters, with a distinct mucosal immune response. SARS-CoV-2-specific mucosal IgA response was substantially generated in subjects boosted with the aerosolized Ad5-nCoV at day 14 post-vaccination. At month 6, participants boosted with the aerosolized Ad5-nCoV had remarkably higher median titer and seroconversion of the Omicron BA.4/5-specific neutralizing antibody than those who received other boosters. DiscussionOur findings suggest that aerosolized Ad5-nCoV may provide an efficient alternative in response to the spread of the Omicron BA.4/5 variant.Clinical trial registrationhttps://www.chictr.org.cn/showproj.html?proj=152729, identifier ChiCTR2200057278

Magnetic Resonance Elastography and Supersonic Shear Imaging : simulation, experimental comparison and application to the characterization of the liver

L’élastographie est une modalité d'imagerie médicale émergente qui permet de mesurer les propriétés mécaniques des tissus moux humains. Ces mesures peuvent servir de biomarqueurs pour l'amélioration de la prise en charge des maladies, du diagnostic précoce et de l'évaluation de la sévérité, au suivi de la réponse au traitement. Parmi les différentes approches de l’élastographie, l'élastographie par Résonance Magnétique (ERM) et l’élastographie ultrasonore par ondes de cisaillement (Supersonic Shear Imaging (SSI)) suscitent des intérêts particuliers. Ces deux modalités ont été largement étudiées pour des applications cliniques multiples. Toutefois, chaque modalité repose sur des conditions d'acquisition et de reconstruction différentes et caractérisées par leur propres limites qui peuvent induire des biais de mesure intra-et inter-modalité et donc entraver l'interchangeabilité des deux modalités pour des applications cliniques. Dans un premier temps, ma thèse a porté sur l'identification des biais de mesure entre ERM et SSI. Grâce à une comparaison méthodologique approfondie des deux modalités, nous avons identifié les différentes caractéristiques de fréquence des ondes de cisaillement générées par les deux modalités et les contraintes spécifiques de reconstruction, en particulier en ERM, comme les principales sources de biais de mesure entre les deux modalités. Dans un deuxième temps, une étude de simulation a étéeffectuée afin de caractériser l'influence des conditions d'acquisition et de reconstruction sur l'exactitude et la précision des mesures d’ERM. Nous avons établi des abaci in silico pour identifier le nombre de voxels par longueur d'onde idéal (rapport λ/a) pour obtenir des mesures ERM exactes et précises. En outre, nous avons montré que le rééchantillonnage pouvait s’avérer efficace afin de répondre aux critères de λ/a favorable lorsque le nombre de voxels par longueur d'onde initial était mal défini. Les résultats finaux, qui sont généralement calculés à partir des trois directions d'encodage, peuvent être améliorés grâce à des stratégies de pondération appropriées qui reposent sur le champ rotationnel du déplacement de l'onde de cisaillement. Pour la modalité SSI, nous avons utilisé le paramètre de qualité fourni par le fabricant afin d’éliminer raisonnablement des résultats peu fiables et améliorer encore la qualité des mesures. Ensuite nous avons intégré les stratégies d'optimisation proposées dans chaque modalité pour effectuer des études de comparaison expérimentales impartiales entre ces deux modalités. Des études in vitro ont été effectuées sur des fantômes commerciaux calibrés et aussi des fantômes à la base de l'alcool polyvinylique. Des résultats expérimentaux confirment bien ceux de la simulation. Des mesures SSI et ERM sont en bon accord quand des biais reliés à la théorie, l'expérimentation et la reconstruction sont minimisés. Des études in vivo ont été ensuite effectuées sur le foie de deux volontaires sains. On a constaté que lorsque le foie est quasi-élastique, des mesures SSI et ERM avec la qualité optimisée concordent bien les uns et les autres, ils sont donc interchangeables. Dans le cas du tissu hépatique viscoélastique, des mesures SSI et ERM dépendent de la fréquence. Dans ce contexte, des mesures ERM et SSI pour la même fréquence spécifique sont nécessaires pour réaliser une comparaison impartiale entre des deux modalités.Elastography is an emerging medical imaging modality which permits to measure the mechanical properties of human soft tissue. The measured mechanical properties can serve as potential biomarkers for improving the management of diseases, from early diagnosis, to severity evaluation and therapy response monitoring. Among different approaches, Magnetic Resonance Elastography (MRE) and Supersonic Shear Imaging (SSI) have shown particular interests. The two modalities have been widely investigated for multiple clinical applications. However, each modality is challenged by specific acquisition and reconstruction conditions which may induce intra- and inter-modality measurement biases and hence impede the interchangeability of the two modalities. The first part of my thesis focused on identifying the measurement biases between MRE and SSI. Through a thorough methodological comparison study, we recognized different frequency characteristics of generated shear waves for the two modalities and modality specific reconstruction validity issues as the main sources for the measurement biases between the two modalities. Then through a dedicated simulation study, we established an in silico abaci to identify the favorable range of number of voxels per wavelength which leads to accurate and precise MRE. Moreover, resampling was proven effective to regulate poorly defined number of voxels per wavelength to the favorable range. The overall outcome, which is usually computed from the three acquired motionencoded directions, may further be improved by appropriate weighting strategies that are based on curl of shear displacement field. For SSI, we referred to the quality parameter provided by the manufacturer to reasonably eliminate unreliable results so as to further improve the measurement quality. After establishing the potential measurement biases between MRE and SSI, we incorporated the proposed quality optimization strategies into both modalities in order to perform unbiased experimental comparison studies between the two modalities. First, in vitro studies were carried out on commercial calibrated phantoms as well as home-made polyvinyl alcohol phantoms. Experimental results corroborate well the simulation findings. MRE and SSI measurements agree well witheach other when theory, experiment, and reconstruction biases are minimized. In vivo studies were then performed on the livers of two healthy volunteers. We found that when the liver is quasi-elastic, the quality-guided MRE and SSI measurements agree well with each other and hence are interchangeable. In case of viscoelastic liver tissue, both MRE and SSI measurements are frequency dependent. Thus frequency-specific measurements are essential for cross-validating the measurements of these two modalities

L'élastographie par résonance magnétique et l'élastographie ultrasonore par ondes de cisaillement supersonic : simulation, comparaison expérimentale et l'application pour la caractérisation du foie

Elastography is an emerging medical imaging modality which permits to measure the mechanical properties of human soft tissue. The measured mechanical properties can serve as potential biomarkers for improving the management of diseases, from early diagnosis, to severity evaluation and therapy response monitoring. Among different approaches, Magnetic Resonance Elastography (MRE) and Supersonic Shear Imaging (SSI) have shown particular interests. The two modalities have been widely investigated for multiple clinical applications. However, each modality is challenged by specific acquisition and reconstruction conditions which may induce intra- and inter-modality measurement biases and hence impede the interchangeability of the two modalities. The first part of my thesis focused on identifying the measurement biases between MRE and SSI. Through a thorough methodological comparison study, we recognized different frequency characteristics of generated shear waves for the two modalities and modality specific reconstruction validity issues as the main sources for the measurement biases between the two modalities. Then through a dedicated simulation study, we established an in silico abaci to identify the favorable range of number of voxels per wavelength which leads to accurate and precise MRE. Moreover, resampling was proven effective to regulate poorly defined number of voxels per wavelength to the favorable range. The overall outcome, which is usually computed from the three acquired motionencoded directions, may further be improved by appropriate weighting strategies that are based on curl of shear displacement field. For SSI, we referred to the quality parameter provided by the manufacturer to reasonably eliminate unreliable results so as to further improve the measurement quality. After establishing the potential measurement biases between MRE and SSI, we incorporated the proposed quality optimization strategies into both modalities in order to perform unbiased experimental comparison studies between the two modalities. First, in vitro studies were carried out on commercial calibrated phantoms as well as home-made polyvinyl alcohol phantoms. Experimental results corroborate well the simulation findings. MRE and SSI measurements agree well witheach other when theory, experiment, and reconstruction biases are minimized. In vivo studies were then performed on the livers of two healthy volunteers. We found that when the liver is quasi-elastic, the quality-guided MRE and SSI measurements agree well with each other and hence are interchangeable. In case of viscoelastic liver tissue, both MRE and SSI measurements are frequency dependent. Thus frequency-specific measurements are essential for cross-validating the measurements of these two modalities.L’élastographie est une modalité d'imagerie médicale émergente qui permet de mesurer les propriétés mécaniques des tissus moux humains. Ces mesures peuvent servir de biomarqueurs pour l'amélioration de la prise en charge des maladies, du diagnostic précoce et de l'évaluation de la sévérité, au suivi de la réponse au traitement. Parmi les différentes approches de l’élastographie, l'élastographie par Résonance Magnétique (ERM) et l’élastographie ultrasonore par ondes de cisaillement (Supersonic Shear Imaging (SSI)) suscitent des intérêts particuliers. Ces deux modalités ont été largement étudiées pour des applications cliniques multiples. Toutefois, chaque modalité repose sur des conditions d'acquisition et de reconstruction différentes et caractérisées par leur propres limites qui peuvent induire des biais de mesure intra-et inter-modalité et donc entraver l'interchangeabilité des deux modalités pour des applications cliniques. Dans un premier temps, ma thèse a porté sur l'identification des biais de mesure entre ERM et SSI. Grâce à une comparaison méthodologique approfondie des deux modalités, nous avons identifié les différentes caractéristiques de fréquence des ondes de cisaillement générées par les deux modalités et les contraintes spécifiques de reconstruction, en particulier en ERM, comme les principales sources de biais de mesure entre les deux modalités. Dans un deuxième temps, une étude de simulation a étéeffectuée afin de caractériser l'influence des conditions d'acquisition et de reconstruction sur l'exactitude et la précision des mesures d’ERM. Nous avons établi des abaci in silico pour identifier le nombre de voxels par longueur d'onde idéal (rapport λ/a) pour obtenir des mesures ERM exactes et précises. En outre, nous avons montré que le rééchantillonnage pouvait s’avérer efficace afin de répondre aux critères de λ/a favorable lorsque le nombre de voxels par longueur d'onde initial était mal défini. Les résultats finaux, qui sont généralement calculés à partir des trois directions d'encodage, peuvent être améliorés grâce à des stratégies de pondération appropriées qui reposent sur le champ rotationnel du déplacement de l'onde de cisaillement. Pour la modalité SSI, nous avons utilisé le paramètre de qualité fourni par le fabricant afin d’éliminer raisonnablement des résultats peu fiables et améliorer encore la qualité des mesures. Ensuite nous avons intégré les stratégies d'optimisation proposées dans chaque modalité pour effectuer des études de comparaison expérimentales impartiales entre ces deux modalités. Des études in vitro ont été effectuées sur des fantômes commerciaux calibrés et aussi des fantômes à la base de l'alcool polyvinylique. Des résultats expérimentaux confirment bien ceux de la simulation. Des mesures SSI et ERM sont en bon accord quand des biais reliés à la théorie, l'expérimentation et la reconstruction sont minimisés. Des études in vivo ont été ensuite effectuées sur le foie de deux volontaires sains. On a constaté que lorsque le foie est quasi-élastique, des mesures SSI et ERM avec la qualité optimisée concordent bien les uns et les autres, ils sont donc interchangeables. Dans le cas du tissu hépatique viscoélastique, des mesures SSI et ERM dépendent de la fréquence. Dans ce contexte, des mesures ERM et SSI pour la même fréquence spécifique sont nécessaires pour réaliser une comparaison impartiale entre des deux modalités

Comparison between 3D Supersonic Shear Wave Elastography and Magnetic Resonance Elastography: a preliminary experimental study

Congrès sous l’égide de la Société Française de Génie Biologique et Médical (SFGBM).National audienceUltrasound Supersonic Shear Wave Elastog-raphy (SSWE) as well as Magnetic Resonance Elastography (MRE) allow accessing the mechanical properties of human tissues. SSWE is usually performed using a 2D probe. 3D SSWE is now available but needs to be validated. We compared 3D SSWE with both 2D SSWE and MRE which is inherently 3D on a breast phantom. We found that 3D SSWE is reproducible and provides elasticity estimates comparable to those obtained with the validated 2D SSWE. We also showed that 3D SSWE and MRE exhibit quite different elasticity moduli , but they reveal similar qualitative trends in the phantom. Although no relationship could be drawn between the two modalities , this study provides a first basis for comparison and a guide for potential improvements