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The study of flow and particle dynamics in microfluidic cross-slot channels is of high relevance for lab-on-a-chip applications. In this work, we investigate the dynamics of a rigid spherical particle in a cross-slot junction for a channel height-to-width ratio of 0.6 and at a Reynolds number of 120 for which a steady vortex exists in the junction area. Using an in-house immersed-boundary-lattice-Boltzmann code, we analyse the effect of the entry position of the particle in the junction and the particle size on the dynamics and trajectory shape of the particle. We find that the dynamics of the particle depend strongly on its lateral entry position in the junction and weakly on its vertical entry position; particles that enter close to the centre show trajectory oscillations. Larger particles have longer residence times in the junction and tend to oscillate less due to their confinement. Our work contributes to the understanding of particle dynamics in intersecting flows and enables the design of optimised geometries for cytometry and particle manipulation.

Introduction: Influenza A is a virus from the Orthomixoviridae family responsible for high lethality rates and morbidity, despite clinically proven vaccination strategies and some anti-viral therapies. The eicosanoid Lipoxin A4 (LXA4) promotes the resolution of inflammation by decreasing cell recruitment and pro-inflammatory cytokines release, but also for inducing activation of apoptosis, efferocytosis, and macrophage reprogramming. Objective: Here, we evaluated whether a synthetic lipoxin mimetic, designated AT-01-KG, would improve the course of influenza A infection in a murine model. Method: Mice were infected with influenza A/H1N1 and treated with AT-01-KG (1.7 μg/kg/day, i.p.) at day 3 post-infection. Results: AT-01-KG attenuated mortality, reducing leukocyte infiltration and lung damage at day 5 and day 7 post-infection. AT-01-KG is a Formyl Peptide Receptor 2 (designated FPR2/3 in mice) agonist, and the protective responses were not observed in fpr2/3 −/− animals. In mice treated with LXA4 (50 μg/kg/day, i.p., days 3–6 post-infection), at day 7, macrophage reprogramming was observed, as seen by a decrease in classically activated macrophages and an increase in alternatively activated macrophages in the lungs. Furthermore, the number of apoptotic cells and cells undergoing efferocytosis was increased in the lavage of treated mice. Treatment also modulated the adaptive immune response, increasing the number of T helper 2 cells (Th2) and regulatory T (Tregs) cells in the lungs of the treated mice. Conclusion: Therefore, treatment with a lipoxin A4 analog was beneficial in a model of influenza A infection in mice. The drug decreased inflammation and promoted resolution and beneficial immune responses, suggesting it may be useful in patients with severe influenza. [ABSTRACT FROM AUTHOR]

Lipoxins are pro‐resolving mediators that play an important role in the resolution phase of the innate inflammatory response. However, because of their chemical and metabolic instability, the design of more stable synthetic analogues of lipoxin A4 and lipoxin B4 is an ongoing area of study. Herein we report the asymmetric synthesis of an aromatic lipoxin B4 analogue containing a conformationally rigid and potentially more metabolically resistant bicyclo[1.1.1]pentane (BCP) ring incorporated into the upper alkyl chain. This was achieved by the development of a 9‐step chiral‐pool synthesis of a novel BCP‐containing boronic ester coupling partner which could serve as a common precursor to the target analogue as well as other analogues with further modifications to the aromatic core. [ABSTRACT FROM AUTHOR]

Lipoxins are an important class of pro-resolving mediators that play a crucial role in the resolution of inflammation. Thus, the synthesis of more metabolically stable synthetic lipoxin analogues is an area of significant interest. Herein the asymmetric synthesis of lipoxin A4 (LXA4) mimetics is reported in which the triene core of the molecule has been replaced by an aromatic sulfur-containing benzothiophene ring. The key steps in the synthesis included a Friedel–Crafts acylation, a Suzuki coupling between two upper and lower chain fragments, and a highly stereoselective Noyori transfer hydrogenation to set the stereochemistry of the alcohol at the benzylic position. A small library of benzothiophene-containing LXA4 analogues with further structural modifications was also successfully synthesised. These included analogues with phenoxy, p -fluorophenoxy, and p -trifluoromethylphenoxy substituents incorporated into the lower alkyl chain with the objective of providing enhanced metabolic stability by blocking ω-oxidation pathways. [ABSTRACT FROM AUTHOR]

Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in refractory epilepsy patients. Accumulating evidence from recent human studies and animal models suggests that seizure-related respiratory arrest may be important for initiating cardiorespiratory arrest and death. Prior evidence suggests that apnea onset can coincide with seizure spread to the amygdala and that stimulation of the amygdala can reliably induce apneas in epilepsy patients, potentially implicating amygdalar regions in seizure-related respiratory arrest and subsequent postictal hypoventilation and cardiorespiratory death. This study aimed to determine if an extended amygdalar structure, the dorsal bed nucleus of the stria terminalis (dBNST), is involved in seizure-induced respiratory arrest (S-IRA) and death using DBA/1 mice, a mouse strain which has audiogenic seizures (AGS) and a high incidence of postictal respiratory arrest and death. The presence of S-IRA significantly increased c-Fos expression in the dBNST of DBA/1 mice. Furthermore, disruption of synaptic output from the dBNST via viral-induced tetanus neurotoxin (TeNT) significantly improved survival following S-IRA in DBA/1 mice without affecting baseline breathing or hypercapnic (HCVR) and hypoxic ventilatory response (HVR). This disruption in the dBNST resulted in changes to the balance of excitatory/inhibitory (E/I) synaptic events in the downstream brainstem regions of the lateral parabrachial nucleus (PBN) and the periaqueductal gray (PAG). These findings suggest that the dBNST is a potential subcortical forebrain site necessary for the mediation of S-IRA, potentially through its outputs to brainstem respiratory regions. [ABSTRACT FROM AUTHOR]

Objective and Design: Here, we evaluated whether a synthetic lipoxin mimetic, designated AT-01-KG, would improve the course of influenza A infection in a murine model., Treatment: Mice were infected with influenza A/H1N1 and treated with AT-01-KG (1.7 mg/kg/day, i.p.) at day 3 post-infection., Methods: Mortality rate was assessed up to day 21 and inflammatory parameters were assessed at days 5 and 7., Results: AT-01-KG attenuated mortality, reducing leukocyte infiltration and lung damage at day 5 and day 7 post-infection. AT-01-KG is a Formyl Peptide Receptor 2 (designated FPR2/3 in mice) agonist, and the protective responses were not observed in FPR2/3 -/- animals. In mice treated with LXA 4 (50mg/kg/day, i.p., days 3-6 post-infection), at day 7, macrophage reprogramming was observed, as seen by a decrease in classically activated macrophages and an increase in alternatively activated macrophages in the lungs. Furthermore, the number of apoptotic cells and cells undergoing efferocytosis was increased in the lavage of treated mice. Treatment also modulated the adaptive immune response, increasing the number of anti-inflammatory T cells (Th2) and regulatory T (Tregs) cells in the lungs of the treated mice., Conclusions: Therefore, treatment with a lipoxin A 4 analog was beneficial in a model of influenza A infection in mice. The drug decreased inflammation and promoted resolution and beneficial immune responses, suggesting it may be useful in patients with severe influenza., Competing Interests: Declaration of Competing Interest The authors have declared that no competing interest exists.

Lipoxins are an important class of pro-resolving mediators that play a crucial role in the resolution of inflammation. Thus, the synthesis of more chemically and metabolically stable synthetic lipoxin analogues is an area of significant interest. Whereas synthetic analogues of lipoxin A 4 (LXA 4 ) have been well studied, analogues of lipoxin B 4 (LXB 4 ) have been the focus of considerably less attention. Herein we report the asymmetric synthesis of a focused library of LXB 4 mimetics in which the triene core of the molecule has been replaced with different aromatic and heteroaromatic rings. The synthesis of each of these analogues was achieved by a general strategy in which the key steps were a Suzuki cross coupling between a common upper chain fragment and an aromatic lower chain, followed by a stereoselective ketone reduction.

Lipoxins are important drivers of inflammation resolution, suggesting a potential therapeutic benefit. Bicyclo[1.1.1]pentanes (BCPs) are potential isosteric replacements for arenes and/or alkyl groups within drug candidates. We carried out an asymmetric synthesis of four BCP-containing synthetic lipoxin A 4 mimetics (BCP-sLXms) in which the key steps were a Suzuki coupling, an asymmetric ketone reduction, and a triethylborane-initiated radical bicyclopentylation. These mimetics were screened for their impact on inflammatory responses, and one imidazolo-BCP-sLXm ( 6a ) was found to possess high anti-inflammatory activity.