New Precoded Spatial-Multiplexing for an Erasure Event in Single Frequency Networks

In this paper, we propose a new spatial-multiplexing(SM) scheme employing an orthogonal precoder over Rayleigh-fading channels for an erasure event in single frequency networks(SFN). To optimize the precoder, the average bit error rate(BER) is evaluated and minimized through a mathematical analysis. Compared to an ordinary SM, the proposed scheme guarantees identical BER performance under non-erasure fading channels and achieves a greatly improved performance under erasure fading channels, especially for a higher erasure-ratio and SNR values. This improvement is mainly due to the increase in the diversity gain incurred by the optimized precoder over the erasure event. We also compare the performance of the proposed SM to that of the conventional constellation-rotation(CR) scheme applied to the single antenna SFN systems. The results of a computer simulation show that the performance of the new scheme is more effective than that of a conventional CR across all simulation cases.

Viral-host molecular interactions and metabolic modulation:Strategies to inhibit flaviviruses pathogenesis

Flaviviruses,which include globally impactful pathogens,such as West Nile virus,yellow fever virus,Zika virus,Japanese encephalitis virus,and dengue virus,contribute significantly to human infections.Despite the ongoing emergence and resurgence of flavivirus-mediated pathogenesis,the absence of specific therapeutic options remains a challenge in the prevention and treatment of flaviviral infections.Through the intricate processes of fusion,transcription,replication,and maturation,the complex interplay of viral and host metabolic interactions affects pathophysiology.Crucial interactions involve metabolic molecules,such as amino acids,glucose,fatty acids,and nucleotides,each playing a pivotal role in the replication and maturation of flaviviruses.These viral-host metabolic molecular interactions hijack and modulate the molecular mechanisms of host metabolism.A comprehensive understanding of these intricate metabolic pathways offers valuable insights,potentially unveiling novel targets for therapeutic interventions against flaviviral pathogenesis.This review emphasizes promising avenues for the development of therapeutic agents that target specific metabolic molecules,such as amino acids,glucose,fatty acids,and nucleotides,which interact with flavivirus replication and are closely linked to the modulation of host metabolism.The clinical limitations of current drugs have prompted the development of new inhibitory strategies for flaviviruses based on an understanding of the molecular interactions between the virus and the host.

Anti-MMP-2 and MMP-9 activity of Salsola komarovii Iljin extract and its solvent fractions

Objective: To investigate matrix metalloproteinases(MMP)-2 and MMP-9 inhibitory effect of Salsola komarovii Iljin, an edible halophyte with health beneficial effects.Methods: Salsola komarovii crude extracts(SKI), and solvent(n-hexane, 85% aq. MeOH, n-BuOH, and H2O) fractionated extracts of SKI were prepared. Gelatin zymography was carried out to observe MMP enzymatic activity. The release of the MMP enzymes was measured by enzyme-linked immunosorbent assay. Expression of MMPs in m RNA and protein level were investigated by polymerase chain reaction analysis and immunoblotting, respectively.Results: SKI and SKI fractions inhibited active MMP-2 and MMP-9 amount in the treated cell culture medium. Also, SKI suppressed the release of MMP-2 and MMP-9 from stimulated HT1080 human fibrosarcoma cells. Furthermore, SKI suppressed the m RNA and protein expression of MMP-2 and MMP-9. SKI fractions showed parallel effects except for H2O fraction which did not yield any significant MMP inhibitory effect. Among fractions, 85% aq. Me OH was the most active fraction to inhibit both the enzymatic effect and expression of MMP-2 and MMP-9.Conclusions: SKI may contain potential MMP release inhibitory compounds. Salsola komarovii is a promising source of compounds against MMP and could be utilized in the development of antitumor agents.

A lipid nanoparticle platform incorporating trehalose glycolipid for exceptional mRNA vaccine safety

The rapid development of messenger RNA(mRNA)vaccines formulated with lipid nanoparticles(LNPs)has contributed to control of the COVID-19 pandemic.However,mRNA vaccines have raised concerns about their potential toxicity and clinical safety,including side effects,such as myocarditis,anaphylaxis,and pericarditis.In this study,we investigated the potential of trehalose glycolipids-containing LNP(LNP S050L)to reduce the risks associated with ionizable lipids.Trehalose glycolipids can form hydrogen bonds with polar biomolecules,allowing the formation of a stable LNP structure by replacing half of the ionizable lipids.The efficacy and safety of LNP S050L were evaluated by encapsulating the mRNA encoding the luciferase reporter gene and measuring gene expression and organ toxicity,respectively.Furthermore,mice immunized with an LNP S050L-formulated mRNA vaccine expressing influenza hemagglutinin exhibited a significant reduction in organ toxicity,including in the heart,spleen,and liver,while sustaining gene expression and immune efficiency,compared to conventional LNPs(Con-LNPs).Our findings suggest that LNP S050L,a trehalose glycolipid-based LNP,could facilitate the development of safe mRNA vaccines with improved clinical safety.