155 research outputs found

    Order structure and topological properties of the set of multiple t-values

    Full text link
    In this paper, we compute the iterated derived sets of the set of multiple t-values under the usual topology of R. Our results imply that the set of multiple t-values, ordered by >=, is a well-ordered set.Comment: 9 page

    Heterosexual HIV-1 infectiousness and antiretroviral use : systematic review of prospective studies of discordant couples

    Get PDF
    Background: Recent studies have estimated the reduction in HIV-1 infectiousness with antiretroviral therapy (ART), but high-quality studies such as randomized controlled trials, accompanied by rigorous adherence counseling, are likely to overestimate the effectiveness of treatment-as-prevention in real-life settings. Methods: We attempted to summarize the effect of ART on HIV transmission by undertaking a systematic review and meta-analysis of HIV-1 infectiousness per heterosexual partnership (incidence rate and cumulative incidence over study follow-up) estimated from prospective studies of discordant couples. We used random-effects Poisson regression models to obtain summary estimates. When possible, the analyses were further stratified by direction of transmission (man-to-woman or woman-to-man) and economic setting (high- or low-income countries). Potential causes of heterogeneity of estimates were explored through subgroup analyses. Results: Fifty publications were included. Nine allowed comparison between ART and non-ART users within studies (ART-stratified studies), in which summary incidence rates were 3.6/100 person-years (95% confidence interval = 2.0-6.5) and 0.2/100 person-years (0.07-0.7) for non-ART- and ART-using couples, respectively (P < 0.001), constituting a 91% (79-96%) reduction in per-partner HIV-1 incidence rate with ART use. The 41 studies that did not stratify by ART use provided estimates with high levels of heterogeneity (I2 statistic) and few reported levels of ART use, making interpretation difficult. Nevertheless, estimates tended to be lower with ART use. Infectiousness tended to be higher for low-income than high-income settings, but there was no clear pattern by direction of transmission (man-to-woman and woman-to-man). Conclusions: ART substantially reduces HIV-1 infectiousness within discordant couples, based on observational studies, and could play a major part in HIV-1 prevention efforts. However, the non-zero risk from partners receiving ART demonstrates that appropriate counseling and other risk-reduction strategies for discordant couples are still required. Additional estimates of ART effectiveness by adherence level from real-life settings will be important, especially for persons starting treatment early without symptoms

    Regulation of bacterial priming and daughter strand synthesis through helicase-primase interactions

    Get PDF
    The replisome is a multi-component molecular machine responsible for rapidly and accurately copying the genome of an organism. A central member of the bacterial replisome is DnaB, the replicative helicase, which separates the parental duplex to provide templates for newly synthesized daughter strands. A unique RNA polymerase, the DnaG primase, associates with DnaB to repeatedly initiate thousands of Okazaki fragments per replication cycle on the lagging strand. A number of studies have shown that the stability and frequency of the interaction between DnaG and DnaB determines Okazaki fragment length. More recent work indicates that each DnaB hexamer associates with multiple DnaG molecules and that these primases can coordinate with one another to regulate their activities at a replication fork. Together, disparate lines of evidence are beginning to suggest that Okazaki fragment initiation may be controlled in part by crosstalk between multiple primases bound to the helicase

    一般社団法人神緑会事業報告

    Get PDF
    Primary central nervous system phaeohyphomycosis is a fatal fungal infection due mainly to the neurotropic melanized fungi Cladophialophora bantiana , Rhinocladiella mackenziei , and Exophiala dermatitidis. Despite the combination of surgery with antifungal treatment, the prognosis continues to be poor, with mortality rates ranging from 50 to 70%. Therefore, a search for a more-appropriate therapeutic approach is urgently needed. Our in vitro studies showed that with the combination of amphotericin B and flucytosine against these species, the median fractional inhibitory concentration (FIC) indices for strains ranged from 0.25 to 0.38, indicating synergy. By use of Bliss independence analysis, a significant degree of synergy was confirmed for all strains, with the sum ΔE ranging from 90.2 to 698.61%. No antagonism was observed. These results indicate that amphotericin B, in combination with flucytosine, may have a role in the treatment of primary cerebral infections caused by melanized fungi belonging to the order Chaetothyriales . Further in vivo studies and clinical investigations to elucidate and confirm these observations are warranted

    Deep Sequencing Whole Transcriptome Exploration of the σE Regulon in Neisseria meningitidis

    Get PDF
    Bacteria live in an ever-changing environment and must alter protein expression promptly to adapt to these changes and survive. Specific response genes that are regulated by a subset of alternative σ70-like transcription factors have evolved in order to respond to this changing environment. Recently, we have described the existence of a σE regulon including the anti-σ-factor MseR in the obligate human bacterial pathogen Neisseria meningitidis. To unravel the complete σE regulon in N. meningitidis, we sequenced total RNA transcriptional content of wild type meningococci and compared it with that of mseR mutant cells (ΔmseR) in which σE is highly expressed. Eleven coding genes and one non-coding gene were found to be differentially expressed between H44/76 wildtype and H44/76ΔmseR cells. Five of the 6 genes of the σE operon, msrA/msrB, and the gene encoding a pepSY-associated TM helix family protein showed enhanced transcription, whilst aniA encoding a nitrite reductase and nspA encoding the vaccine candidate Neisserial surface protein A showed decreased transcription. Analysis of differential expression in IGRs showed enhanced transcription of a non-coding RNA molecule, identifying a σE dependent small non-coding RNA. Together this constitutes the first complete exploration of an alternative σ-factor regulon in N. meningitidis. The results direct to a relatively small regulon indicative for a strictly defined response consistent with a relatively stable niche, the human throat, where N. meningitidis resides

    Piezoelectric polymer composites for sensors and actuators

    Get PDF
    As a result of the Internet of Things (IoT) and Industry 4.0 paradigms, based on increasing interconnectivity, the development of advanced high-performance materials for sensor and actuator applications are increasingly required. In particular, piezoelectric composites are of large scientific and technological interest from fundamental and applied point of views. Piezoelectric composites are applied in a wide range of applications as they combine the excellent properties of polymers and ceramics. The definition and properties of piezoelectric materials and composites are presented as well as the recent applications in areas such as electronics, energy harvesting, environmental sensors and biomedical applications. The outlook and future trends for piezoelectric composites are also provided.FCT (Fundação para a Ciência e Tecnologia) for financial support under the framework of Strategic Funding grants UID/FIS/04650/2020, UID/EEA/04436/2020 and UID/QUI/0686/2020; and project no. PTDC/FISMAC/28157/2017, PTDC/BTM-MAT/28237/2017 and PTDC/EMDEMD/28159/2017. The authors also thank the FCT for financial support under grants SFRH/BD/145455/2019 (E.C.), SFRH/BD/145345/2019 (L.F.) and SFRH/BPD/112547/2015 (C.M.C.). Financial support from the Basque Government Industry and Education Departments under the ELKARTEK, HAZITEK and PIBA (PIBA-2018-06

    Gender differences in the use of cardiovascular interventions in HIV-positive persons; the D:A:D Study

    Get PDF
    Peer reviewe
    corecore