Formal [3+2] Cycloaddition Reactions of Electron-Rich Aryl Epoxides with Alkenes under Lewis Acid Catalysis Affording Tetrasubstituted Tetrahydrofurans

We report on the regio- and stereoselective synthesis of tetrahydrofurans by reaction between epoxides and alkenes in the presence of a Lewis acid. This is an unprecedented formal [3+2] cycloaddition reaction between an epoxide and an alkene. The chemical reaction represents a very concise synthesis of tetrahydrofurans from accessible starting compounds

Aspectos de la biología floral del género Sarcocapnos DC. (Fumariaceae)

Aspectos de la biología floral del género Sarcocapnos DC. (Fumariaceae). Se describe la fenología de la floración y de la fructificación de tres especies del género Sarcocapnos, así como algunos aspectos de la biología floral (biometría de flores, carga polínica sobre el estigma, presencia de tubos polínicos sobre el mismo, número medio de granos de polen por flor, relación P/O, biometría de frutos y número medio de semillas viables por fruto) de las siete especies que integran el género. Se concluye que éstas presentan un conjunto de caracteres que favorecen la polinización cruzada, a diferencia de las afirmaciones de otros autores que las consideran predominantemente autógama

Centaurea boissieri DC. and C. resupinata Coss. (Asteraceae) in the Iberian Peninsula

Sobre la base de un estudio taxonómico previo del grupo de Centaurea boissieri DC., previamente reconocido como sección Willkommia Blanca, se estudian las dos especies con mayor área de distribución geográfica y que presentan gran complejidad taxonómica. Se reconocen 7 subespecies en C. boissieri DC. y 2 en C. resupinata Coss. en la Península Ibérica. Se aporta una clave de identificación de las subespecies e información sobre la distribución geográfica, apetencias ecológicas y variabilidad morfológica relacionada con procesos de introgresión con otras especies. Se propone una nueva combinación: C. boissieri subsp. integrifolia (Willk.) Blanca & Suár.-Sant

Aspectos de la biología floral del género Sarcocapnos DC. (Fumariaceae).

RESUMEN. Aspectos de la biología floral del género Sarcocapnos DC. (Fumariaceae). Se describe la fenología de la floración y de la fructificación de tres especies del género Sarcocapnos, así como algunos aspectos de la biología floral (biometría de flores, carga polínica sobre el estigma, presencia de tubos polínicos sobre el mismo, número medio de granos de polen por flor, relación P/O, biometría de frutos y número medio de semillas viables por fruto) de las siete especies que integran el género. Se concluye que éstas presentan un conjunto de caracteres que favorecen la polinización cruzada, a diferencia de las afirmaciones de otros autores que las consideran predominantemente autógamas.Palabras clave. Biometría floral, casmófitos, endemismos, fenología, floración, fructificación, Fumariaceae, relación polen/óvulos, Sarcocapnos.ABSTRACT. Floral biology of genus Sarcocapnos DC. (Fumariaceae). The phenology of flowering and fruiting is described in three species of the genus Sarcocapnos. In addition, some aspects of the floral biology (biometry of flowers, pollen load, the presence of pollen tubes on the stigma, the mean number of pollen grains per flower, the P/0 relationship, the biometry of fruits and the mean number of viable seeds per fruit) have been calculated for the seven species comprising this genus. It is concluded that these present a group of traits giving rise to allopollinization, in contrast to the conclusions of other works characterizing these plants as predominantly autogairious.Key words. Chasmophytes, endemic species, floral biometry, flowering, fruiting, Fumariaceae, phenology, polen/ovule ratios, Sarcocapnos

Phylogeographical Analyses of a Relict Fern of Palaeotropical Flora (Vandenboschia speciosa): Distribution and Diversity Model in Relation to the Geological and Climate Events of the Late Miocene and Early Pliocene

Samira Ben-Menni Schuler was granted a predoctoral grant (F.P.U. program) from the Spanish Government. Hammadi Hamza was granted by a postdoctoral fellowship (Erasmus Mundus-Al Idrisi II scholarship) from the European Union. The authors thank all those people and institutions that facilitated or helped in the collection of samples (in alphabetical order: angel Banares, Antonio Delgado, Brother Anthony, Government of Ireland, Elizabeth Ojeda, Emer Ni Dhuill, Gobierno de Canarias, Ibai Olariaga-Ibarguren, Inaki Sanz-Azkue, Junta de Andalucia, Kristyna Hanuova, Miguel Perez-Gutierrez, Parque Nacional de Garajonay, Ranger Brian Duffy, Sito Chinea, Yves Krippel). We also thank Ana Garcia-Garcia for technical assistance in SDM analysis. This research was funded by the Regional Andalusian Government, grant number P10-RNM-6198.Fern phylogeographic studies have mostly focused on the influence of the Pleistocene climate on fern distributions and the prevalence of long-distance dispersal. The effect of pre-Pleistocene events on the distributions of fern species is largely unexplored. Here, we elucidate a hypothetical scenario for the evolutionary history of Vandenboschia speciosa, hypothesised to be of Tertiary palaeotropical flora with a peculiar perennial gametophyte. We sequenced 40 populations across the species range in one plastid region and two variants of the nuclear gapCp gene and conducted time-calibrated phylogenetic, phylogeographical, and species distribution modelling analyses. Vandenboschia speciosa is an allopolyploid and had a Tertiary origin. Late Miocene aridification possibly caused the long persistence in independent refugia on the Eurosiberian Atlantic and Mediterranean coasts, with the independent evolution of gene pools resulting in two evolutionary units. The Cantabrian Cornice, a major refugium, could also be a secondary contact zone during Quaternary glacial cycles. Central European populations resulted from multiple post-glacial, long-distance dispersals. Vandenboschia speciosa reached Macaronesia during the Pliocene–Pleistocene, with a phylogeographical link between the Canary Islands, Madeira, and southern Iberia, and between the Azores and northwestern Europe. Our results support the idea that the geological and climate events of the Late Miocene/Early Pliocene shifted Tertiary fern distribution patterns in Europe.Spanish Government European Commission(Erasmus Mundus-Al Idrisi II scholarship) from the European Union - Regional Andalusian Government P10-RNM-619

Genetic diversity and structure of the narrow endemic species Crepis granatensis: implications for conservation

In this study, we studied the genetic diversity and population genetic structure of the endangered endemic Crepis granatensis, using amplified fragments length polymorphism (AFLP) and plastid DNA (cpDNA). No genetic divergences were obtained using cpDNA markers. Three primers combinations selected from a total of 12 produced a total of 421 fragments, of which 418 (99.3%) were polymorphic. The total genetic diversity of C. granatensis was moderate (Ht = 0.260). Neís gene diversity ranged from 0.202 to 0.258. The fixation index (Fst) was 0.137, suggesting low to moderate genetic differentiation among populations. The AMOVA analysis revealed that genetic diversity was mainly concentrated among individuals within populations (74%), while 8% was found among populations and 18% among regions. The Bayesian analysis and PCoA identified two genetic clusters: one corresponded to La Sagra population and the other corresponded to the Mágina populations. Based on our genetic results, it is necessary to preserve the evolutionary potential of C. granatensis by protecting all extant populations. Both in situ and ex-situ conservation measures should be considered. Reinforcement, reintroduction, and translocation programmes could be performed if necessary. Finally, such conservation strategies should be considered both in the current recovery plan and management actions for the species.Departamento de Biología Vegetal de la Universidad de Murcia, Departamento de Botánica de la Universidad de Granad

The Role of INAPERTURATE POLLEN1 as a Pollen Aperture Factor Is Conserved in the Basal Eudicot Eschscholzia californica (Papaveraceae)

This study was supported by the Spanish Ministry of Economy and Competitiveness (project CGL2015-70290-P to VS-S) and by the US National Science Foundation (MCB-1817835 to AD). IM-A was supported by a predoctoral grant (F.P.I. program) from the Spanish Government. BK was supported by the Ministry of Education, Youth and Sports of the Czech Republic (project LTC20050) and DH was supported by Czech Science Foundation (project 21-15856S).Pollen grains show an enormous variety of aperture systems. What genes are involved in the aperture formation pathway and how conserved this pathway is in angiosperms remains largely unknown. INAPERTURATE POLLEN1 (INP1) encodes a protein of unknown function, essential for aperture formation in Arabidopsis, rice and maize. Yet, because INP1 sequences are quite divergent, it is unclear if their function is conserved across angiosperms. Here, we conducted a functional study of the INP1 ortholog from the basal eudicot Eschscholzia californica (EcINP1) using expression analyses, virus-induced gene silencing, pollen germination assay, and transcriptomics. We found that EcINP1 expression peaks at the tetrad stage of pollen development, consistent with its role in aperture formation, which occurs at that stage, and showed, via gene silencing, that the role of INP1 as an important aperture factor extends to basal eudicots. Using germination assays, we demonstrated that, in Eschscholzia, apertures are dispensable for pollen germination. Our comparative transcriptome analysis of wildtype and silenced plants identified over 900 differentially expressed genes, many of them potential candidates for the aperture pathway. Our study substantiates the importance of INP1 homologs for aperture formation across angiosperms and opens up new avenues for functional studies of other aperture candidate genes.Spanish Ministry of Economy and Competitiveness CGL2015-70290-PNational Science Foundation (NSF) MCB-1817835Spanish Government European CommissionMinistry of Education, Youth & Sports - Czech Republic LTC20050Grant Agency of the Czech Republic 21-15856

Development of polymorphic microsatellite markers for the Killarney Fern (Vandenboschia speciosa, Hymenophyllaceae)

Premise of the study: We characterize 10 microsatellite loci in the endangered fern Vandenboschia speciosa (Hymenophyllaceae), enabling studies on the genetic population structure of this Macaronesian-European species using DNA hypervariable markers. Methods and Results: Ten primer sets were developed and tested on 47 individuals in a total of two Iberian populations of V. speciosa. The primers amplified di- and hexanucelotide repeats. The number of alleles ranged from two to eight, and the expected heterozygosity ranged from 0.107 to 0.807 among the populations analyzed. Conclusions: The 10 microsatellite markers developed will be useful in characterizing the genetic diversity of V. speciosa and understanding its population structure (including the possible structure between sporophyte and gametophyte phases) and biogeographic history, and will provide important genetic data for the conservation of this species.This study was supported by the Regional Andalusian Government (project P10-RNM-6198). C.G.L. was funded by a postdoctoral grant from the Regional Andalusian Government. S.B.S. and L.T.C. were funded by a Beca-Iniciación a la Investigación grant from the Universidad de Granada during 2012–2013 and 2014–2015, respectively. I.M.A. was funded by a Beca-Colaboración grant (Spanish Government)

Choice of the initial antiretroviral treatment for HIV-positive individuals in the era of integrase inhibitors

BACKGROUND: We aimed to describe the most frequently prescribed initial antiretroviral therapy (ART) regimens in recent years in HIV-positive persons in the Cohort of the Spanish HIV/AIDS Research Network (CoRIS) and to investigate factors associated with the choice of each regimen. METHODS: We analyzed initial ART regimens prescribed in adults participating in CoRIS from 2014 to 2017. Only regimens prescribed in >5% of patients were considered. We used multivariable multinomial regression to estimate Relative Risk Ratios (RRRs) for the association between sociodemographic and clinical characteristics and the choice of the initial regimen. RESULTS: Among 2874 participants, abacavir(ABC)/lamivudine(3TC)/dolutegavir(DTG) was the most frequently prescribed regimen (32.1%), followed by tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC)/elvitegravir(EVG)/cobicistat(COBI) (14.9%), TDF/FTC/rilpivirine (RPV) (14.0%), tenofovir alafenamide (TAF)/FTC/EVG/COBI (13.7%), TDF/FTC+DTG (10.0%), TDF/FTC+darunavir/ritonavir or darunavir/cobicistat (bDRV) (9.8%) and TDF/FTC+raltegravir (RAL) (5.6%). Compared with ABC/3TC/DTG, starting TDF/FTC/RPV was less likely in patients with CD4100.000 copies/mL. TDF/FTC+DTG was more frequent in those with CD4100.000 copies/mL. TDF/FTC+RAL and TDF/FTC+bDRV were also more frequent among patients with CD4<200 cells//μL and with transmission categories other than men who have sex with men. Compared with ABC/3TC/DTG, the prescription of other initial ART regimens decreased from 2014-2015 to 2016-2017 with the exception of TDF/FTC+DTG. Differences in the choice of the initial ART regimen were observed by hospitals' location. CONCLUSIONS: The choice of initial ART regimens is consistent with Spanish guidelines' recommendations, but is also clearly influenced by physician's perception based on patient's clinical and sociodemographic variables and by the prescribing hospital location.The RIS cohort (CoRIS) is supported by the Instituto de Salud Carlos III through the Red Temática de Investigación Cooperativa en Sida (RD06/006, RD12/0017/0018 and RD16/0002/0006) as part of the Plan Nacional I+D+i and cofinanced by ISCIII-Subdirección General de Evaluación and the Fondo Europeo de Desarrollo Regional (FEDER). This study was funded by ViiV Healthcare. ViiV Healthcare was given the opportunity to review a preliminary version of this manuscript for factual accuracy. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The authors are solely responsible for final content and interpretation of the results.S

Low variability of single-molecule conductance assisted by bulky metal-molecule contacts

A detailed study of the trimethylsilylethynyl moiety, –C[triple bond]CSiMe3 (TMSE) , as an anchoring group in metalmoleculemetal junctions, using a combination of experiment and density functional theory is presented. It is shown that the TMSE anchoring group provides improved control over the molecule-substrate arrangement within metalmoleculemetal junctions, with the steric bulk of the methyl groups limiting the number of highly transmissive binding sites at the electrode surface, resulting in a single sharp peak in the conductance histograms recorded by both the in situ break junction and I(s) STM techniques. As a consequence of the low accessibility of the TMSE group to surface binding configurations of measurable conductance, only about 10% of gold break junction formation cycles result in the clear formation of molecular junctions in the experimental histograms. The DFT-computed transmission characteristics of junctions formed from the TMSE-contacted oligo(phenylene)ethynylene (OPE)-based molecules described here are dominated by tunneling effects through the highest-occupied molecular orbitals (HOMOs). This gives rise to similar conductance characteristics in these TMSE-contacted systems as found in low conductance-type junctions based on comparably structured OPE-derivatives with amine-contacts that also conduct through HOMO-based channels.R. R. F. thanks the Consejería de Educación del Principado de Asturias for a Severo Ochoa grant (BP11-069). V. M. G.-S. thanks the Spanish Ministerio de Economía y Competitividad for a Ramón y Cajal fellowship (RYC-2010-06053). R. R. F., J. F. and V. M. G.-S. wish to acknowledge financial support from the Spanish grant FIS2012-34858 and the Marie Curie Network MOLESCO. P. C. and S. M. are grateful for financial assistance from the Ministerio de Economía y Competitividad of Spain in the framework of the project CTQ2012-33198 as well as the award of the CTQ2013-50187-EXP grant. H. M. O., P. C., and S. M. thank the support from DGA and Fondos FEDER for funding through the Platon research group. H. M. O. is also grateful for financial assistance from the Secretaría Nacional de Educación Superior, Ciencia, Tecnología e Innovaciín from Ministerio de Educación (Ecuador). S. M. thanks the Ministerio de Educación from Spain for financial support through the framework of the Campus de Excelencia Internacional, CEI Iberus. S. J. H., R. J. N., P. J. L. and S. M.-G. thank the EPSRC for funding (EPSRC grants EP/K007785/1, EP/H035184/1, EP/K007548/1, EP/H005595/1). P. J. L. holds an Australian Research Council Future Fellowship (FT120100073) and gratefully acknowledges funding for this work from the ARC (DP140100855).Peer Reviewe