2,333 research outputs found
Interferon regulatory factor 1 protects against chikungunya virus-induced immunopathology by restricting infection in muscle cells
The interferon-stimulated gene IFITM3 restricts infection and pathogenesis of arthritogenic and encephalitic alphaviruses
Host cells respond to viral infections by producing type I interferon (IFN), which induces the expression of hundreds of interferon-stimulated genes (ISGs). Although ISGs mediate a protective state against many pathogens, the antiviral functions of the majority of these genes have not been identified. IFITM3 is a small transmembrane ISG that restricts a broad range of viruses, including orthomyxoviruses, flaviviruses, filoviruses, and coronaviruses. Here, we show that alphavirus infection is increased in Ifitm3(ā/ā) and Ifitm locus deletion (Ifitm-del) fibroblasts and, reciprocally, reduced in fibroblasts transcomplemented with Ifitm3. Mechanistic studies showed that Ifitm3 did not affect viral binding or entry but inhibited pH-dependent fusion. In a murine model of chikungunya virus arthritis, Ifitm3(ā/ā) mice sustained greater joint swelling in the ipsilateral ankle at days 3 and 7 postinfection, and this correlated with higher levels of proinflammatory cytokines and viral burden. Flow cytometric analysis suggested that Ifitm3(ā/ā) macrophages from the spleen were infected at greater levels than observed in wild-type (WT) mice, results that were supported by experiments with Ifitm3(ā/ā) bone marrow-derived macrophages. Ifitm3(ā/ā) mice also were more susceptible than WT mice to lethal alphavirus infection with Venezuelan equine encephalitis virus, and this was associated with greater viral burden in multiple organs. Collectively, our data define an antiviral role for Ifitm3 in restricting infection of multiple alphaviruses. IMPORTANCE The interferon-induced transmembrane protein 3 (IFITM3) inhibits infection of multiple families of viruses in cell culture. Compared to other viruses, much less is known about the antiviral effect of IFITM3 on alphaviruses. In this study, we characterized the antiviral activity of mouse Ifitm3 against arthritogenic and encephalitic alphaviruses using cells and animals with a targeted gene deletion of Ifitm3 as well as deficient cells transcomplemented with Ifitm3. Based on extensive virological analysis, we demonstrate greater levels of alphavirus infection and disease pathogenesis when Ifitm3 expression is absent. Our data establish an inhibitory role for Ifitm3 in controlling infection of alphaviruses
Complexes of Sn(IV) with Schiff Bases Derived from Salicylaldehyde/Acetylacetone & o-Aminophenol, o-Aminobenzothiol & o-Aminobenzoic Acid*
589-59
Study of crystal structure and PL properties of Na21Mg(SO4)10Cl3 :Ce halophosphor
A new phosphor Na21Mg(SO4)10Cl3 is very interesting for photoluminescence (PL) properties. In this paper we present results concerning the main PL properties of Na21Mg(SO4)10Cl3 activated by Ce at various concentrations. Polycrystalline Na21Mg(SO4)10Cl3: Ce phosphor prepared by wet chemical method have been studied for its PL characteristics showing Ce3+ emission at 341 nm at the excitation of 247 nm due to 5d → 4f transition, This is a good result for the materials which can be used in scintillation applications
A Sub-Terahertz Sliding Correlator Channel Sounder with Absolute Timing using Precision Time Protocol over Wi-Fi
Radio channels at mmWave and sub-THz frequencies for 5G and 6G communications
offer large channel bandwidths (hundreds of MHz to several GHz) to achieve
multi-Gbps data rates. Accurate modeling of the radio channel for these wide
bandwidths requires capturing the absolute timing of multipath component (MPC)
propagation delays with sub-nanosecond accuracy. Achieving such timing accuracy
is challenging due to clock drift in untethered transmitter (TX) and receiver
(RX) clocks used in time-domain channel sounders, yet will become vital in many
future 6G applications. This paper proposes a novel solution utilizing
precision time protocol (PTP) and periodic drift correction to achieve absolute
timing for MPCs in power delay profiles (PDPs) --captured as discrete samples
using sliding correlation channel sounders. Two RaspberryPi computers are
programmed to implement PTP over a dedicated Wi-Fi link and synchronize the TX
and RX Rubidium clocks continuously every second. This synchronization
minimizes clock drift, reducing PDP sample drift to 150 samples/hour, compared
to several thousand samples/hour without synchronization. Additionally, a
periodic drift correction algorithm is applied to eliminate PDP sample drift
and achieve sub-nanosecond timing accuracy for MPC delays. The achieved
synchronicity eliminates the need for tedious and sometimes inaccurate ray
tracing to synthesize omnidirectional PDPs from directional measurements. The
presented solution shows promise in myriad applications, including precise
position location and distributed systems that require sub-nanosecond timing
accuracy and synchronization among components.Comment: 6 pages, 7 figures, 3 tables, IEEE Global Communications Conference
(GLOBECOM) 202
DEVELOPMENT OF THERMOSENSITIVE GEL OF FLUCONAZOLE FOR VAGINAL CANDIDIASIS
Objective: The aim of the present study was to develop in-situ gelling formulations of Fluconazole (FCZ) using thermosensitive polymer for treatment of vaginal Candidiasis.Methods: In-situ gelling formulations of FCZ (1 % w/w) were prepared with different concentrations of Poloxamer 407 (P 407, 15-20% w/w) using the cold dispersion method. Similarly, ĆĀ formulations were also prepared by adding mucoadhesive polymers like hydroxyethyl cellulose, Polycarbophil, Carbopol 974 and Hydroxypropyl methylcellulose E 50 LV (0.4 % w/w) to the P 407 formulations. These formulations were evaluated for appearance, clarity, pH, gelling ability, gelling time, gelling temperature, viscosity (in sol and gel forms), spreading time, ex-vivo mucoadhesion, in-vitro dissolution, morphological characteristics by SEM and in-vitro antifungal efficacy against Candida albicance. In-vivo vaginal irritation of developed formulation was assessed in New Zealand female rabbits. Results: In-situ gelling formulation of FCZ, prepared using 18 % w/w P407 and 0.4 % hydroxyethyl cellulose, was optimized since this formulation was found to be clear, transparent, forming a quick and stable gel with shear thinning behaviour and excellent mucoadhesion. The developed formulation released 74.21% of FCZ after 8 h of dissolution in 5.2 pH citrate buffer. In-vitro antifungal activity against Candida albicance showed the stronger antifungal activity of formulation as compared to a marketed formulation. In-vivo vaginal irritation study in rabbits demonstrated no significant irritation after 10 d of exposure to the formulation. Conclusion: The study demonstrated that in-situ gelling formulation of FCZ prepared using thermosensitive polymer had improved activity against Candida albicance and would be efficacious for the treatment of vaginal Candidiasis
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