815 research outputs found

    Exact Wave Functions for Generalized Harmonic Oscillators

    Full text link
    We transform the time-dependent Schroedinger equation for the most general variable quadratic Hamiltonians into a standard autonomous form. As a result, the time-evolution of exact wave functions of generalized harmonic oscillators is determined in terms of solutions of certain Ermakov and Riccati-type systems. In addition, we show that the classical Arnold transformation is naturally connected with Ehrenfest's theorem for generalized harmonic oscillators.Comment: 10 pages, no figure

    On The Harmonic Oscillator Group

    Full text link
    We discuss the maximum kinematical invariance group of the quantum harmonic oscillator from a view point of the Ermakov-type system. A six parameter family of the square integrable oscillator wave functions, which seems cannot be obtained by the standard separation of variables, is presented as an example. The invariance group of generalized driven harmonic oscillator is shown to be isomorphic to the corresponding Schroedinger group of the free particle.Comment: 11 pages, no figure

    TRPC6 channels are required for proliferation, migration and invasion of breast cancer cell lines by modulation of Orai1 and Orai3 surface exposure

    Get PDF
    Transient receptor potential channels convey signaling information from a number of stimuli to a wide variety of cellular functions, mainly by inducing changes in cytosolic Ca2+ concentration. Different members of the TRPC, TRPM and TRPV subfamilies have been reported to play a role in tumorigenesis. Here we show that the estrogen receptor positive and triple negative breast cancer cell lines, MCF7 and MDA-MB-231, respectively, exhibit enhanced expression of the TRPC6 channel as compared to the non-tumoral MCF10A cell line. In vitro TRPC6 knockdown using shRNA impaired MCF7 and MDA-MB-231 cell proliferation, migration and invasion detected by BrdU incorporation, wound healing and Boyden chamber assays, respectively. Using RNAi-mediated TRPC6 silencing as well as overexpression of the pore-dead dominant-negative TRPC6 mutant we have found that TRPC6 plays a relevant role in the activation of store-operated Ca2+ entry in the breast cancer cell lines but not in non-tumoral breast cells. Finally, we have found that TRPC6 interacts with Orai1 and Orai3 in MCF7 and MDA-MB-231 cells and is required for the translocation of Orai1 and Orai3 to the plasma membrane in MDA-MB-231 and MCF7 cells, respectively, upon Ca2+ store depletion. These findings introduce a novel mechanism for the modulation of Ca2+ influx and the development of different cancer hallmarks in breast cancer cells

    Novel genes and sex differences in COVID-19 severity

    Get PDF
    Sex differences; COVID-19Diferències de sexe; COVID-19Diferencias de sexo; COVID-19Here, we describe the results of a genome-wide study conducted in 11 939 coronavirus disease 2019 (COVID-19) positive cases with an extensive clinical information that were recruited from 34 hospitals across Spain (SCOURGE consortium). In sex-disaggregated genome-wide association studies for COVID-19 hospitalization, genome-wide significance (P < 5 × 10−8) was crossed for variants in 3p21.31 and 21q22.11 loci only among males (P = 1.3 × 10−22 and P = 8.1 × 10−12, respectively), and for variants in 9q21.32 near TLE1 only among females (P = 4.4 × 10−8). In a second phase, results were combined with an independent Spanish cohort (1598 COVID-19 cases and 1068 population controls), revealing in the overall analysis two novel risk loci in 9p13.3 and 19q13.12, with fine-mapping prioritized variants functionally associated with AQP3 (P = 2.7 × 10−8) and ARHGAP33 (P = 1.3 × 10−8), respectively. The meta-analysis of both phases with four European studies stratified by sex from the Host Genetics Initiative (HGI) confirmed the association of the 3p21.31 and 21q22.11 loci predominantly in males and replicated a recently reported variant in 11p13 (ELF5, P = 4.1 × 10−8). Six of the COVID-19 HGI discovered loci were replicated and an HGI-based genetic risk score predicted the severity strata in SCOURGE. We also found more SNP-heritability and larger heritability differences by age (<60 or ≥60 years) among males than among females. Parallel genome-wide screening of inbreeding depression in SCOURGE also showed an effect of homozygosity in COVID-19 hospitalization and severity and this effect was stronger among older males. In summary, new candidate genes for COVID-19 severity and evidence supporting genetic disparities among sexes are provided.Instituto de Salud Carlos III (COV20_00622 to A.C., COV20/00792 to M.B., COV20_00181 to C.A., COV20_1144 to M.A.J.S., PI20/00876 to C.F.); European Union (ERDF) ‘A way of making Europe’. Fundación Amancio Ortega, Banco de Santander (to A.C.), Estrella de Levante S.A. and Colabora Mujer Association (to E.G.-N.) and Obra Social La Caixa (to R.B.); Agencia Estatal de Investigación (RTC-2017-6471-1 to C.F.), Cabildo Insular de Tenerife (CGIEU0000219140 ‘Apuestas científicas del ITER para colaborar en la lucha contra la COVID-19’ to C.F.) and Fundación Canaria Instituto de Investigación Sanitaria de Canarias (PIFIISC20/57 to C.F.)

    Utility of MF-non coding region for measles molecular surveillance during post-elimination phase, Spain, 2017-2020

    Get PDF
    Background: In countries entering the post-elimination phase for measles, the study of variants by sequencing of 450 nucleotides of the N gene (N450) does not always allow the tracing of chains of transmission. Indeed, between 2017 and 2020, most measles virus sequences belonged to either the MVs/Dublin.IRL/8.16 (B3-Dublin) or the MVs/Gir Somnath.IND/42.16 (D8-Gir Somnath) variants. We evaluated the additional use of a non-coding region (MF-NCR) as a tool to enhance resolution and infer case origin, chains of transmission and characterize outbreaks. Methods: We obtained 115 high-quality MF-NCR sequences from strains collected from Spanish patients infected with either B3-Dublin or D8-Gir Somnath variants between 2017 and 2020, performed epidemiological, phylogenetic and phylodynamic analyses and applied a mathematical model to determine relatedness among identified clades. Results: Applying this model allowed us to identify phylogenetic clades potentially derived from concomitant importations of the virus rather than single chain of transmission, inferred based on only N450 and epidemiology data. In a third outbreak, we found two related clades that corresponded to two chains of transmission. Discussion: Our results show the ability of the proposed method to improve identification of simultaneous importations in the same region which could trigger enhanced contact tracing. Moreover, the identification of further transmission chains indicates that the size of import-related outbreaks was smaller than previously found, supporting the interpretation that endemic measles transmission was absent in Spain between 2017 and 2020. We suggest considering the use of the MF-NCR region in conjunction with the study of N450 variants in future WHO recommendations for measles surveillance.This work was supported by the “Instituto de Salud Carlos III” (PI15CIII/00023, PI19ICIII/0041). AG was funded by CIBER de Epidemiología y Salud Pública (CIBERESP), ISCIII. CJ was funded by the ECDC/EUPHEM fellowship.S

    Chia (Salvia hispanica L.) products as ingredients for reformulating frankfurters: Effects on quality properties and shelf-life

    Get PDF
    Several strategies were examined for incorporating chia products (seeds, flour and a coproduct from cold-press oil extraction) in frankfurters. The nutritional composition, technological properties and sensory attributes of the resulting products were studied in relation to the formulation used and, lipid oxidation, pH, residual nitrite level and microbiological properties were evaluated during chilled storage. Application of these chia products (3%) was seen to enhance the nutritional composition of frankfurters, without adversely affecting the technological properties of the final product. In general, although differences were detected in the sensory attributes of the frankfurters reformulated with chia products (most of them when chia coproduct was added), all of them were judged acceptable. Besides the quality aspects, these reformulation strategies had beneficial effects on some technological properties during chilled storage: better resistance to oxidation (controlling the TBARS increase during storage) and lower residual nitrite levels than control (both effects presumably because the chia polyphenols content) and no effect on microbiological safet
    corecore