High-salt diet suppresses autoimmune demyelination by regulating the blood-brain barrier permeability

Sodium chloride, "salt," is an essential component of daily food and vitally contributes to the body's homeostasis. However, excessive salt intake has often been held responsible for numerous health risks associated with the cardiovascular system and kidney. Recent reports linked a high-salt diet (HSD) to the exacerbation of artificially induced central nervous system (CNS) autoimmune pathology through changes in microbiota and enhanced T(H)17 cell differentiation [M. Kleinewietfeld et al., Nature 496, 518-522 (2013); C. Wu et al., Nature 496, 513-517 (2013); N. Wilck et al., Nature 551, 585-589 (2017)]. However, there is no evidence that dietary salt promotes or worsens a spontaneous autoimmune disease. Here we show that HSD suppresses autoimmune disease development in a mouse model of spontaneous CNS autoimmunity. We found that HSD consumption increased the circulating serum levels of the glucocorticoid hormone corticosterone. Corticosterone enhanced the expression of tight junction molecules on the brain endothelial cells and promoted the tightening of the blood-brain barrier (BBB) thereby controlling the entry of inflammatory T cells into the CNS. Our results demonstrate the multifaceted and potentially beneficial effects of moderately increased salt consumption in CNS autoimmunity.We thank the Mass Spectrometry and NGS Core Facilities at the Max Planck Institute of Biochemistry for performing sample analysis for proteomics and mRNA-seq experiments

Antibacterial activity of diff erent solvent extracts of Caulerpa chemnitzia (Esper) J.V. Lamououx, from Mandapam, Gulf of Mannar Southeast Coast, Tamil Nadu, India

Phytochemical analyses and in vitro antibacterial activity of different extracts of hexane, chloroform, ethyl acetate,acetone, and methanol extracts of green algae, Caulerpa chemnitzia (Esper) J.V. Lamououx, against Bacillussubtilis, Streptococcus pyogenes, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris,Pseudomonas aeruginosa, Salmonella typhimurium, Shigella flexneri, and Vibrio cholerae. The extent of theinhibitory zone, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) weredetermined. The ethyl acetate extract of C. chemnitzia showed the presence of phytochemicals, terpenoids,tannins and phenolic compounds strongly than the other solvent extracts. The mean zone of inhibition producedby the extracts in agar diffusion assays against the tested bacterial strains ranged from 7.1 to 13.6 mm. The MICwas between 125 and 500 μg/mL while the MBC were between 250 and 1000 μg/mL. The highest mean zoneof inhibition (13.6 mm) and the lowest MIC (125 μg/mL) and MBC (250 μg/mL) values were observed in ethylacetate extract against B. subtilis. These findings suggest that the ethyl acetate extract of C. chemnitzia can beused as an antibacterial substance for the treatment of bacteria causing acquired infection

Approximate Bipartite bb-Matching using Multiplicative Auction

Given a bipartite graph $G(V= (A \cup B),E)$ with $n$ vertices and $m$ edges and a function $b \colon V \to \mathbb{Z}_+$, a $b$-matching is a subset of edges such that every vertex $v \in V$ is incident to at most $b(v)$ edges in the subset. When we are also given edge weights, the Max Weight $b$-Matching problem is to find a $b$-matching of maximum weight, which is a fundamental combinatorial optimization problem with many applications. Extending on the recent work of Zheng and Henzinger (IPCO, 2023) on standard bipartite matching problems, we develop a simple auction algorithm to approximately solve Max Weight $b$-Matching. Specifically, we present a multiplicative auction algorithm that gives a $(1 - \varepsilon)$-approximation in $O(m \varepsilon^{-1} \log \varepsilon^{-1} \log \beta)$ worst case time, where $\beta$ the maximum $b$-value. Although this is a $\log \beta$ factor greater than the current best approximation algorithm by Huang and Pettie (Algorithmica, 2022), it is considerably simpler to present, analyze, and implement.Comment: 14 pages; Accepted as a refereed paper in the 2024 INFORMS Optimization Society conferenc

Screening of phytochemical and antibacterial potential of diff erent organic solvent extracts of Stoechospermum marginatum (Ag) Kutz. from Manappad coast, Tuticorin District, South India

The antibacterial activity of different extracts of hexane, chloroform, ethyl acetate, acetone and methanol extractof a brown alga, Stoechospermum marginatum (Ag) Kutz. against Bacillus subtilis, Streptococcus pyogenes,Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, Salmonellatyphimurium, Shigella flexneri and Vibrio cholerae. The extent of the inhibitory zone, Minimum InhibitoryConcentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined. The ethyl acetateextract of S. marginatum showed the highest antibacterial activity against all the bacterial strains tested thanthe other extracts. The mean zones of inhibition produced by the extracts in agar diffusion assays against thetested bacterial strains ranged from 7.1 to 18.1 mm. The MIC were between 125 and 500 μg/ml, while theMBC were between 250 and 1000 μg/ml. The ethyl acetate extract of S. marginatum showed the presenceof terpenoids, tannins, phenolic compounds and steroids strongly than the other solvent extracts. The highestmean of zone inhibition (18.1 mm) was observed in the ethyl acetate extract of S. marginatum against B. subtilis.These finding suggest that the ethyl acetate extract of S. marginatum can be used as an antibacterial substancefor the treatment of bacterial infections

Topological Transitions in Metamaterials

The ideas of mathematical topology play an important role in many aspects of modern physics - from phase transitions to field theory to nonlinear dynamics (Nakahara M (2003) in Geometry, Topology and Physics, ed Brewer DF (IOP Publishing Ltd, Bristol and Philadelphia), Monastryskiy M (1987) in Riemann Topology and Physics, (Birkhauser Verlag AG)). An important example of this is the Lifshitz transition (Lifshitz IM (1960) Anomalies of electron characteristics of a metal in the high-pressure region, Sov Phys JETP 11: 1130-1135), where the transformation of the Fermi surface of a metal from a closed to an open geometry (due to e.g. external pressure) leads to a dramatic effect on the electron magneto-transport (Kosevich AM (2004) Topology and solid-state physics. Low Temp Phys 30: 97-118). Here, we present the optical equivalent of the Lifshitz transition in strongly anisotropic metamaterials. When one of the components of the dielectric permittivity tensor of such a composite changes sign, the corresponding iso-frequency surface transforms from an ellipsoid to a hyperboloid. Since the photonic density of states can be related to the volume enclosed by the iso-frequency surface, such a topological transition in a metamaterial leads to a dramatic change in the photonic density of states, with a resulting effect on every single physical parameter related to the metamaterial - from thermodynamic quantities such as its equilibrium electromagnetic energy to the nonlinear optical response to quantum-electrodynamic effects such as spontaneous emission. In the present paper, we demonstrate the modification of spontaneous light emission from quantum dots placed near the surface of the metamaterial undergoing the topological Lifshitz transition, and present the theoretical description of the effect

Accumulation of trace metals in green mussel Perna viridis in the shellfish harvesting environment along southern Karnataka coast

The levels of trace metals, Cd, Pb, Cu, Zn, Ni and Fe in seawater and their bioaccumulation in green mussel Perna viridis were examined in two shellfish harvesting environments, Someshwara and Surathkal, along the southern Karnataka coast. In seawater, the concentration of trace metals analysed were below the levels causing harmful effects on the larvae and adult mussels, set by the European Council Directive 79/923/EEC. The Fe, Ni, Cd and Zn levels in mussel tissue from Surathkal were relatively higher when compared to that of mussel tissue samples from Someshwara while Cu and Pb levels were lower. The mean tissue concentrations of trace metals in the soft tissue of P. viridis from shellfish waters were found to be safe and below the permissible concentrations for seafood (US FDA and WHO) as well as EU limits in marine products