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This paper presents a coupling method between the computational fluid dynamics (CFD) code and the computational structure dynamics (CSD) code solver for computing the trim of a flexible turbine in a vessel tank. It is applied in order to predict the equilibrium of elastic blade in fluid turbulent flow. Since the fluid and the structural models differ in their formulation and discretization, an interface model has to be introduced that represents the connectivity and physical interaction between the two single domain models. The structure is represented by finite elements and the related equations are solved using CSD code. The fluid flow is described by the three-dimensional Eider equations, solved by CFD code. The resulting coupled field problem containing the fluid and the structural state equations is solved by applying a coupling algorithm. In each solution step the interface and boundary conditions are exchanged and updated. [ABSTRACT FROM AUTHOR]

The frequencies of murine B-cell precursors developing into clones secreting antibodies which bind to autologous (mouse) or heterologous (rabbit or human) forms of the same protein antigen (myosin and albumin) were determined in an attempt to directly test the hypothesis of higher decay rates of B lymphocytes exposed to sell-antigens. The results exclude, on a quantitative basis, any form of inactivation or deletion of such cells. [ABSTRACT FROM AUTHOR]

Acute myocardial infarction (AMI) is one of the leading causes of death worldwide. Cell apoptosis in the myocardium plays an important role in ischemia and reperfusion (I/R) injury, leading to cardiac damage and dysfunction. Platelets are major players in hemostasis and play a crucial role in vessel occlusion, inflammation, and cardiac remodeling after I/R. Here, we studied the impact of platelets on cell apoptosis in the myocardium using a close-chest mouse model of AMI. We found caspase-3-positive resident cardiac cells, while leukocytes were negative for caspase-3. Using two different mouse models of thrombocytopenia, we detected a significant reduction in caspase-3 positive cells in the infarct border zone after I/R injury. Further, we identified platelet FasL to induce cell apoptosis via the extrinsic pathway of Fas receptor activation of target cells. Mechanistically, hypoxia triggers platelet adhesion to FasR, suggesting that platelet-induced apoptosis is elevated after I/R. Platelet-specific FasL knock-out mice showed reduced Bax and Bcl2 expression, suggesting that platelets modulate the intrinsic and extrinsic pathways of apoptosis, leading to reduced infarct size after myocardial I/R injury. Thus, a new mechanism for how platelets contribute to tissue homeostasis after AMI was identified that should be validated in patients soon., Competing Interests: The authors declare no conflicts of interest.

Invariant natural killer T (NKT) cell subsets are defined based on their cytokine-production profiles and transcription factors. Their distribution is different in C57BL/6 (B6) and BALB/c mice, with a bias for NKT1 and NKT2/NKT17 subsets, respectively. Here, we show that the non-classical class I-like major histocompatibility complex CD1 molecules CD1d2, expressed in BALB/c and not in B6 mice, could not account for this difference. We find however that NKT cell subset distribution is intrinsic to bone marrow derived NKT cells, regardless of syngeneic CD1d-ligand recognition, and that multiple intrinsic factors are likely involved. Finally, we find that CD1d expression levels in combination with T cell antigen receptor signal strength could also influence NKT cell distribution and function. Overall, this study indicates that CD1d-mediated TCR signals and other intrinsic signals integrate to influence strain-specific NKT cell differentiation programs and subset distributions., (© 2023. The Author(s).)

Fas ligand is increased in several immune-mediated diseases, including acute graft-versus-host disease, a donor cell-mediated disorder post-hematopoietic stem cell transplantation. In this disease, Fas ligand is involved in T-cell-mediated damage to host tissues. However, the role of its expression on donor non-T cells has, so far, never been addressed. Using a well-established CD4- and CD8-mediated graft-versus-host disease murine model, we found that precocious gut damage and mice mortality are increased with a graft of donor T- and B-depleted bone marrow cells devoid of Fas ligand as compared with their wild-type counterparts. Interestingly, serum levels of both soluble Fas ligand and IL-18 are drastically reduced in the recipients of Fas ligand-deficient grafts, indicating that soluble Fas ligand stems from donor bone marrow-derived cells. In addition, the correlation between the concentrations of these 2 cytokines suggests that IL-18 production arises through a soluble Fas ligand-driven mechanism. These data highlight the importance of Fas ligand-dependent production in IL-18 production and in mitigating acute graft-versus-host disease. Overall, our data reveal the functional duality of Fas ligand according to its source., (© The Author(s) 2023. Published by Oxford University Press on behalf of Society for Leukocyte Biology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

In this study, we focused on evaluating the responses of the cockle, Cerastoderma glaucum to in situ exposures to metals at three sites in the Gulf of Gabes in the coastal zone of Tunisia differing in levels of metal contamination. Firstly, we examined the general physiological state of the organisms. Secondly, we evaluated the bioaccumulation of several metals (Cd, Cu, Zn, Ni) in the cockles. Thirdly, we focused on evaluating histologically changes in gametogenesis and sexual maturity of the organisms. Finally, we determined the expression of seven key genes encoding enzymes or proteins involved in responses to different types of environmental stressors. Results showed a decrease in the general physiological status of the cockles, including a reduced condition index, sex ratios skewed to females (70% and 80% females in the intermediate and the contaminated site, respectively) and greater mortalities in tests under anoxic conditions (i.e., stress on stress test) in cockles collected from the most contaminated site (LT50 = 2.88 days) compared to the cockles from the intermediate site (LT50 = 5 days) and the less contaminated site (LT50 = 6 days). Results for metal bioaccumulation showed that the levels of Cd, Cu, Zn and Ni in cockles were consistent with the contaminant gradient, with the highest levels in cockles from the most contaminated site (1.04; 4.92; 52.76 and 13.81 µg/g dw, respectively), followed by those from the intermediate site (0.34; 2.94; 36.94; 17.40 µg/g dw, respectively) and then the less contaminated site (0.065; 1.27; 21.62 and 5.40 µg/g dw, respectively). Results from the gametogenesis and maturity index showed few differences in the reproductive cycle of cockles collected from the three study sites. There were different patterns of gene expression that were divided into three groups in terms of responses: (1) expression of genes involved in metal detoxification, ATP Binding Cassette Subfamily B Member 1 (ABCB1) and metallothionein MT) and genes for superoxide dismutases (i.e., Mn SOD and CuZn SOD), which did not show any difference in their levels of expression; (2) heat shock protein 70 (HSP70) gene expression, which decreased in cockles according to the pollution gradient, and (3) expression of catalase (CAT) and cytochrome oxidase subunit 1 (COI) genes was threefold and 1000-fold higher in cockles from intermediate and most contaminated sites compared to the less contaminated site. Therefore, changes in overall physiological condition, sex ratios and expression of HSP70, CAT and COI genes may be appropriate biomarkers for in situ studies of the impacts of metals in cockles. However, these biomarkers should be coupled to proteomics studies., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)