4d F(4) gauged supergravity and black holes of class ℱ

We perform a consistent reduction of 6d matter-coupled F(4) supergravity on a compact Riemann surface $$ {\Sigma}_{\mathfrak{g}} $$ Σ g of genus $$ \mathfrak{g} $$ g , at the level of the bosonic action. The result is an $$ \mathcal{N} $$ N = 2 gauged supergravity coupled to two vector multiplets and a single hypermultiplet. The four-dimensional model is holographically dual to the 3d superconformal field theories of class ℱ, describing different brane systems in massive type IIA and IIB wrapped on $$ {\Sigma}_{\mathfrak{g}} $$ Σ g . The naive reduction leads to a non-standard 4d mixed duality frame with both electric and magnetic gauge fields, as well as a massive tensor, that can be only described in the embedding tensor formalism. Upon a chain of electromagnetic dualities, we are able to determine the scalar manifolds and electric gaugings that uniquely specify the model in the standard supergravity frame. We then use the result to construct the first examples of static dyonic black holes in AdS6 and perform a microscopic counting of their entropy via the 5d topologically twisted index. Finally, we show the existence of further subtruncations to the massless sector of the 4d theory, such as the Fayet-Iliopoulos gauged T3 model and minimal gauged supergravity. We are in turn able to find new asymptotically AdS4 solutions, providing predictions for the squashed S3 partition functions and the superconformal and refined twisted indices of class ℱ theories.

Quantification of Moss-Associated Cyanobacteria Using Phycocyanin Pigment Extraction

In the boreal forest, cyanobacteria can establish associations with feather moss and realize the biological nitrogen fixation (BNF) reaction, consisting in the reduction of atmospheric dinitrogen into bioavailable ammonium. In this ecosystem, moss-associated cyanobacteria are the main contributors to BNF by contributing up to 50% of new N input. Current environmental changes driven by anthropogenic activities will likely affect cyanobacteria activity (i.e., BNF) and populations inhabiting mosses, leading to potential important consequences for the boreal forest. Several methods are available to efficiently measure BNF activity, but quantifying cyanobacteria biomass associated with moss is challenging because of the difficulty to separate bacteria colonies from the host plant. Attempts to separate cyanobacteria by shaking or sonicating in water were shown to be poorly efficient and repeatable. The techniques commonly used, microscopic counting and quantitative PCR (qPCR) are laborious and time-consuming. In aquatic and marine ecosystems, phycocyanin (PC), a photosynthesis pigment produced by cyanobacteria, is commonly used to monitor cyanobacteria biomass. In this study, we tested if PC extraction and quantification can be used to estimate cyanobacteria quantity inhabiting moss. We report that phycocyanin can be easily extracted from moss by freeze/thaw disturbance of cyanobacteria cells and can be quickly and efficiently measured by spectrofluorometry. We also report that phycocyanin extraction is efficient (high recovery), repeatable (relative SD < 13%) and that no significant matrix effects were observed. As for aquatic systems, the main limitation of cyanobacteria quantification using phycocyanin is the difference of cellular phycocyanin content between cyanobacteria strains, suggesting that quantification can be impacted by cyanobacteria community composition. Nonetheless, we conclude that phycocyanin extraction and quantification is an easy, rapid, and efficient tool to estimate moss-associated cyanobacteria number.

Multiplexed Droplet Loop-mediated Isothermal Amplification with Scorpion-shaped Probes and Fluorescence Microscopic Counting for Digital Quantification of Virus RNAs

Highly sensitive digital nucleic acid techniques are of great significance for the prevention and control of epidemic diseases. Here we report the development of multiplex droplet loop-mediated isothermal amplification (multiplexed...

Anti-parasitic Effects of Herbal Extract-Based Silver Nanoparticles on the Trophozoite and Cystic Forms of Acanthamoeba Protozoa

Background: Acanthamoeba is a globally dispersed protozoan that can cause different clinical manifestations in infected individuals. Various drugs have been proposed against its drug-resistant forms. Objective: The present study examined silver nanoparticles (NPs) with a good anti-parasitic background. More precisely, the study focused on evaluating the anti-parasitic effect of silver nano-scale particles on protozoan trophozoite and cysts by microscopic counting and flow cytometry after exposure to different concentrations. Methods: To this end, MTT assay and IC50 were used to assess the macrophage toxicity and cysts/trophozoites, respectively. Results: Based on the results, 100 ppm silver NPs had better anti-parasitic effects than 80 ppm concentration and even the standard treatment of Acanthamoeba on both trophozoite and cystic phases. Macrophages toxicity at 100 ppm concentration was similar to the control group. Conclusion: In general, further studies should be conducted to confirm the present results given the significant effects of silver NPs against trophozoite and parasite cysts.

Significant correlation between meibomian gland dysfunction and keratitis in young patients with Demodex brevis infestation

AimsTo report the clinical characteristics and correlation between meibomian gland dysfunction (MGD) and keratitis in young patients with ocular demodicosis.MethodsObservational case series of 60 patients younger than 35 years with ocular demodicosis, of which the diagnosis was based on microscopic counting of Demodex folliculorum and D. brevis of epilated lashes. Severity of keratitis and MGD was graded by photography and meibography, respectively, in a masked fashion.ResultsMGD was detected in 54/60 (90%) patients with the loss of meibomian gland in the upper lid more than the lower lid (p<0.001). Blepharoconjunctivitis and a variety of corneal pathologies were noted in 47/60 (78.3%) and 39/60 (65%) patients, respectively. For a total of 120 eyes, normal cornea was noted in 53 (44.2%) eyes, superficial punctate keratitis or limbitis was noted in 17 (14.2%), while corneal stromal infiltration was found in 50 (41.7%) eyes. Both univariate and multivariate analyses showed that the severity of meibomian gland loss was significantly correlated with higher D. brevis count and more severe keratitis (all p<0.05). Rapid resolution of keratitis and blepharoconjunctivitis was accompanied by significant reduction of the Demodex count in 48 patients receiving lid scrub directed to kill mites.ConclusionsThere is a significant correlation between MGD and keratitis in young patients with ocular demodicosis especially inflicted by D. brevis.

Cationic Liposomal Sodium Stibogluconate (SSG), a Potent Therapeutic Tool for Treatment of Infection by SSG-Sensitive and -Resistant Leishmania donovani

ABSTRACTPentavalent antimonials have been the first-line treatment for leishmaniasis for decades. However, the development of resistance to sodium stibogluconate (SSG) has limited its use, especially for treating visceral leishmaniasis (VL). The present work aims to optimize a cationic liposomal formulation of SSG for the treatment of both SSG-sensitive (AG83) and SSG-resistant (GE1F8R and CK1R)Leishmania donovaniinfections. Parasite killing was determined by the 3-(4,5-dimethylthiazol-2)-2,5-diphenyltetrazolium bromide (MTT) assay and microscopic counting of Giemsa-stained macrophages. Macrophage uptake studies were carried out by confocal microscopic imaging. Parasite-liposome interactions were visualized through transmission electron microscopy. Toxicity tests were performed using assay kits. Organ parasite burdens were determined by microscopic counting and limiting dilution assays. Cytokines were measured by enzyme-linked immunosorbent assays (ELISAs) and flow cytometry. Although all cationic liposomes studied demonstrated leishmanicidal activity, phosphatidylcholine (PC)-dimethyldioctadecylammonium bromide (DDAB) vesicles were most effective, followed by PC-stearylamine (SA) liposomes. Since entrapment of SSG in PC-DDAB liposomes demonstrated enhanced ultrastructural alterations in promastigotes, PC-DDAB-SSG vesicles were further investigatedin vitroandin vivo. PC-DDAB-SSG could effectively alleviate SSG-sensitive and SSG-resistantL. donovaniinfections in the liver, spleen, and bone marrow of BALB/c mice at a dose of SSG (3 mg/kg body weight) not reported previously. The parasiticidal activity of these vesicles was attributed to better interactions with the parasite membranes, resulting in direct killing, and generation of a strong host-protective environment, necessitating a very low dose of SSG for effective cures.