Lossy mode resonance sensors based on tungsten oxide thin films

Tungsten oxide (WO3) thin-films fabricated on glass slides have been proven to generate lossy mode resonances (LMRs) in the visible region. Obtained devices were characterized in transmission by lateral incidence of light on the edge of glass slides. Resonances at both TE and TM polarizations were analyzed for different thicknesses and in different deposition conditions. Moreover, it was successfully proved that WO3 coated glass slides present a high sensitivity to refractive index, which opens the path to the application of this structure in the domain of optical sensors.This work was supported in part by the Spanish Agencia Estatal de Investigación (AEI) through project PID2019-106231RB-I00 and by Italian Ministry of University and Research (MIUR) through the University Research Project 2017 (prot. RG11715C8213BD81)

Nanocoated fiber label-free biosensing for perfluorooctanoic acid detection by lossy mode resonance

The determination of per- and polyfluoroalkyl substances (PFAS) in environmental samples, such as drinking waters, requires the design of high performing and versatile sensing strategies. Label-free biosensing platforms based on specialty fiber optics are a valid option to face this challenge. Among them, lossy mode resonance (LMR) fiber optic biosensors are showing remarkable performance in terms of detection limit, selectivity, and reproducibility. The detection of small molecules, such as perfluorooctanoic acid (PFOA), can be achieved with the help of well-designed biological recognition layers. In this study, the biosensing potentialities of a label-free LMR-assisted optical platform based on nanocoated fibers are investigated. Delipidated human serum albumin (hSA) was used as biological recognition layer for PFOA in aqueous solution. Different fiber functionalization protocols based on the covalent immobilization of hSA were tested. The conformational changes related to the formation of hSA/PFOA complex were followed via optical monitoring of LMR spectral shift, showing a trend that can be modeled with Langmuir adsorption isotherm. These results confirmed the potentiality of LMR-based fiber biosensors for the detection of small molecules, such as PFOA, in synthetic samples

Viroids, the simplest RNA replicons: How they manipulate their hosts for being propagated and how their hosts react for containing the infection

[EN] The discovery of viroids about 45 years ago heralded a revolution in Biology: small RNAs comprising around 350 nt were found to be able to replicate autonomously and to incite diseases in certain plants without encoding proteins, fundamental properties discriminating these infectious agents from viruses. The initial focus on the pathological effects usually accompanying infection by viroids soon shifted to their molecular features they are circular molecules that fold upon themselves adopting compact secondary conformations and then to how they manipulate their hosts to be propagated. Replication of viroids in the nucleus or chloroplasts through a rolling-circle mechanism involving polymerization, cleavage and circularization of RNA strands dealt three surprises: (i) certain RNA polymerases are redirected to accept RNA instead of their DNA templates, (ii) cleavage in chloroplastic viroids is not mediated by host enzymes but by hammerhead ribozymes, and (iii) circularization in nuclear viroids is catalyzed by a DNA ligase redirected to act upon RNA substrates. These enzymes (and ribozymes) are most probably assisted by host proteins, including transcription factors and RNA chaperones. Movement of viroids, first intracellularly and then to adjacent cells and distal plant parts, has turned out to be a tightly regulated process in which specific RNA structural motifs play a crucial role. More recently, the advent of RNA silencing has brought new views on how viroids may cause disease and on how their hosts react to contain the infection; additionally, viroid infection may be restricted by other mechanisms. Representing the lowest step on the biological size scale, viroids have also attracted considerable interest to get a tentative picture of the essential characteristics of the primitive replicons that populated the postulated RNA world. (C) 2015 Elsevier B.V. All rights reserved.Research in R.F. laboratory is currently funded by grants BFU2011-28443 and ACOMP/2014/A/103 from the Spanish Ministerio de Economia y Competitividad (MINECO) and Generalidad Valenciana, respectively. S.M., S.D. and A.L.-C. have been supported by fellowships or contracts from MINECO. Research in B.N. and F.D.S. laboratory has been funded by a dedicated grant of the Ministero dell'Economia e Finanze Italian to the CNR (CISIA, Legge n. 191/2009).Flores Pedauye, R.; Minoia, S.; Carbonell, A.; Gisel, A.; Delgado Villar, SG.; López-Carrasco, MA.; Navarro, B.... (2015). Viroids, the simplest RNA replicons: How they manipulate their hosts for being propagated and how their hosts react for containing the infection. Virus Research. 209:136-145. https://doi.org/10.1016/j.virusres.2015.02.027S13614520

Role of RNA silencing in plant-viroid interactions and in viroid pathogenesis

[EN] Viroids are small, single-stranded, non-protein coding and circular RNAs able to infect host plants in the absence of any helper virus. They may elicit symptoms in their hosts, but the underlying molecular pathways are only partially known. Here we address the role of post-transcriptional RNA silencing in plant-viroid-interplay, with major emphasis on the involvement of this sequence-specific RNA degradation mechanism in both plant antiviroid defence and viroid pathogenesis. This review is a tribute to the memory of Dr. Ricardo Flores, who largely contributed to elucidate this and other molecular mechanisms involved in plant-viroid interactions.The authors of this manuscript, former PhD students, post-doctoral fellows and colleagues of Dr. Ricardo Flores, would like to dedicate this review to his memory. Among many other achievement during his scientific career, Ricardo was responsible for major advances in efforts to dissect the molecular mechanisms underlying viroid pathogenesis. An exemplary and dedicated scientist, excellent mentor, and a treasured friend, Ricardo will be deeply missed.Di Serio, F.; Owens, RA.; Navarro, B.; Serra, P.; Martínez De Alba, AE.; Delgado Villar, SG.; Carbonell, A.... (2023). Role of RNA silencing in plant-viroid interactions and in viroid pathogenesis. Virus Research. 323:1-6. https://doi.org/10.1016/j.virusres.2022.1989641632

Club Drugs and Psychiatric Sequelae: An Issue of Vulnerability and Previous Psychiatric History

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).The pursuit of pleasure among clubbers and disco-goers often involves drug use. However, whether substance use may represent a relevant risk factor contributing to the development of psychiatric symptoms and of mental illness remains debated. The purposes of this study were to evaluate the percentage of subjects who developed long-lasting psychiatric symptoms in a sample of subjects reporting use of substances in nightclubs, and to evaluate the role of a previous psychiatric diagnosis in these subjects. Data were collected during three consecutive years in dedicated nursing units inside all the nightclubs of Ibiza, in emergency hospital rooms at the Can Misses Hospital and inside the psychiatric ward. A total of 10,163 subjects required medical assistance inside discos in the medical-nursing units, of which 223 required transfers to hospital emergency rooms. Of these, 110 required subsequent psychiatric hospitalization. Ninety-one (82.7 %) of these patients had a positive psychiatric history, which was also found in thirty-one of the 113 subjects (27.4%) not requiring psychiatric hospitalization. Negative psychiatric history was negatively associated with hospitalization (Coefficient = −2.574; p = 0.000) and for subjects with a negative psychiatric history the odds to be hospitalized changed by a factor of 0.076. Gender, age, civil status and nationality were not significant predictors of hospitalization. Overall, the number of subjects who developed major psychiatric disorders appeared to be limited. However, the presence of a psychiatric history here played a crucial role. Club drugs are therefore able to induce psychiatric sequelae requiring hospitalization mainly in subjects who are already vulnerable from a psychopathological point of view.Peer reviewedFinal Published versio

Viroid RNA turnover: characterization of the subgenomic RNAs of potato spindle tuber viroid accumulating in infected tissues provides insights into decay pathways operating in vivo

[EN] While biogenesis of viroid RNAs is well-known, how they decay is restricted to data involving host RNA silencing. Here we report an alternative degradation pathway operating on potato spindle tuber viroid (PSTVd), the type species of nuclear-replicating viroids (family Pospiviroidae). Northern-blot hybridizations with full-and partial-length probes revealed a set of PSTVd (+) subgenomic (sg) RNAs in early-infected eggplant, some partially overlapping and reaching levels comparable to those of the genomic circular and linear forms. Part of the PSTVd (+) sgRNAs were also observed in Nicotiana benthamiana (specifically in the nuclei) and tomato, wherein they have been overlooked due to their low accumulation. Primer extensions of representative (+) sgRNAs failed to detect a common 5' terminus, excluding that they could result from aborted transcription initiated at one specific site. Supporting this view, 5'- and 3'-RACE indicated that the (+) sgRNAs have 5'-OH and 3'-P termini most likely generated by RNase-mediated endonucleolytic cleavage of longer precursors. These approaches also unveiled PSTVd (-) sgRNAs with features similar to their (+) counterparts. Our results provide a mechanistic insight on how viroid decay may proceed in vivo during replication, and suggest that synthesis and decay of PSTVd strands might be coupled as in mRNA.Ministerio de Economia y Competitividad (MINECO) [BFU2011-28443 to R. F. laboratory]; MINECO [to S.M. and S.D.]. Funding for open access charge: MINECO (BFU2011-28443 to R. F.); Ministero dell'Economia e Finanze Italiano to the CNR (CISIA, Legge 191/2009 to B.N. and F.D.S.).Minoia, S.; Navarro, B.; Delgado Villar, SG.; Di Serio, F.; Flores Pedauye, R. (2015). Viroid RNA turnover: characterization of the subgenomic RNAs of potato spindle tuber viroid accumulating in infected tissues provides insights into decay pathways operating in vivo. Nucleic Acids Research. 43(4):2313-2325. https://doi.org/10.1093/nar/gkv034S2313232543

Cytopathic effects incited by viroid RNAs and putative underlying mechanisms

[EN] Viroids are infectious agents identified only in plants so far. In contrast to viruses, the genome of viroids is composed of a tiny circular RNA (250-400 nt) not coding for proteins, but containing in its compact structure all the information needed for parasitizing the transcriptional and RNA trafficking machineries of their hosts. Viroid infections are frequently accompanied by cellular and developmental disorders that ultimately result in macroscopic symptoms.The molecular events linking the structural domains of viroid RNAs with cellular and macroscopic alterations remain largely unexplored, although significant progress has been lately achieved in one specific viroid-host combination, highlighting the ability of viroids to strongly interfere with their host RNA regulatory networks. Cytopathic effects induced by nuclear-replicating viroids, which were investigated since early studies on viroids, consist in irregular proliferations of cell membranes (paramural bodies or plasmalemmasomes), cell wall distortions, and chloroplast malformations. Different alternatives have been proposed regarding how these cytological alterations may influence the onset of macroscopic symptoms. Recently, the cytopathology and histopathology incited by a chloroplast-replicating viroid have been investigated in depth, with defects in chloroplast development having been related to specific molecular events that involve RNA silencing and impairment of chloroplast ribosomal RNA maturation. On this basis, a tentative model connecting specific cytopathologic alterations with symptoms has been put forward. Here, early and more recent studies addressing this issue will be reviewed and reassessed in the light of recent advances in the regulatory roles of small RNAs.Research in Beatriz Navarro and Francesco Di Serio laboratory is supported by a dedicated grant (CISIA) of the Ministero dell'Economia e Finanze Italiano to the CNR (Legge n. 191/2009). Research in Ricardo Flores laboratory is presently supported by grant BFU2011-28443 from the Ministerio de Ciencia e Innovacion of Spain. We apologize for not quoting the original work of many authors due to space limitations.Di Serio, F.; De Stradis, A.; Delgado Villar, SG.; Flores Pedauye, R.; Navarro, B. (2013). Cytopathic effects incited by viroid RNAs and putative underlying mechanisms. Frontiers in Plant Science. 3:288-1-288-7. https://doi.org/10.3389/fpls.2012.00288288-1288-7