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来源:PASJ: Publications of the Astronomical Society of Japan , 2019

作者:Satyal, Suman, Cuntz, Manfred

关键词:celestial mechanics;astrobiology;...

使用许可:CC BY

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The aim of our study is to explore the possible existence of Earth-mass planets in the habitable zone of 55 Cancri, an effort pursued based on detailed orbital stability simulations. This star is known to possess (at least) five planets with masses ranging between super-Earth and Jupiter-type. Additionally, according to observational constraints, there is a space without planets between ∼0.8 au and ∼5.7 au, and it is noted that the inner part of this gap largely coincides with 55 Cnc’s habitable zone—a sincere motivation for the search of potentially habitable planets. It has previously been argued that terrestrial habitable planets are able to exist in the 55 Cnc system, including a planet at ∼1.5 au. We explore this possibility through employing sets of orbital integrations and assuming an integration time of 50 Myr. We found that the possibility of Earth-mass planets in the system’s habitable zone strongly depends on the adopted system parameters, notably the eccentricity of 55 Cnc-f, which is controversial as both a high value (e ∼ 0.32) and a low value (e ∼ 0.08) have previously been deduced. In the case where the low value, the more plausible and most recent value, is adopted (together with other updates for the system parameters), Earth-mass planets would be able to exist in the gap between 1.0 au and 2.0 au, thus implying the possibility of habitable system planets. Thus, 55 Cnc should be considered a favorable target for future habitable planet search missions.

    来源:Diseases of Aquatic Organisms , 2019

    作者:Andr D. Gendron

    关键词:Host response;Gene transcription;...

    使用许可:Unknown

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    Freshwater unionoid mussels have a unique life cycle involving a temporary parasitic phase. Their larvae (glochidia) attach to the gills or fins of fish hosts where they remain encysted until metamorphosis into free-living juveniles. The physiological response of fish during the critical period of glochidial attachment is not well understood, but recent work suggests that glochidia retention and survival is enhanced in stressed and cortisol-injected hosts. In this study, the early changes induced by glochidiosis were investigated for the first time at the transcriptional level. In 2 separate experiments, juvenile yellow perch Perca flavescens were inoculated with glochidia of Elliptio complanata (a host generalist) and Lampsilis radiata (a host specialist) following a standardized procedure. The transcriptional levels of 5 genes involved in the fish response to stress were assessed in the host liver and gills 24 h post-infection using quantitative real-time PCR. The number of encysted glochidia did not significantly differ between fish inoculated with E. complanata and L. radiata. Both species induced a 3-fold increase of 70 kDa heat-shock protein gene (hsp70) transcription in host liver. However, only E. complanata influenced the transcription of cortisol-regulated genes, notably glucocorticoid receptor DNA-binding factor 1 (grlf1). This gene, known to modulate tissue responsiveness to cortisol, was downregulated in infected fish compared to controls. Our findings suggest that different glochidia species interact with their fish host in distinct ways. Additional studies are required to address this hypothesis and further investigate the significance of the observed host transcriptional responses.

      来源:Cell Death & Disease , 2019

      作者:Simona Anticoli;Barbara Ascione;Paola Matarrese;等

      使用许可:CC BY

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      Sex dimorphism in cell response to stress has previously been investigated by different research groups. This dimorphism could be at least in part accounted for by sex-biased expression of regulatory elements such as microRNAs (miRs). In order to spot previously unknown miR expression differences we took advantage of prior knowledge on specialized databases to identify X chromosome-encoded miRs potentially escaping X chromosome inactivation (XCI). MiR-548am-5p emerged as potentially XCI escaper and was experimentally verified to be significantly up-regulated in human XX primary dermal fibroblasts (DFs) compared to XY ones. Accordingly, miR-548am-5p target mRNAs, e.g. the transcript for Bax, was differently modulated in XX and XY DFs. Functional analyses indicated that XY DFs were more prone to mitochondria-mediated apoptosis than XX ones. Experimentally induced overexpression of miR548am-5p in XY cells by lentivirus vector transduction decreased apoptosis susceptibility, whereas its down-regulation in XX cells enhanced apoptosis susceptibility. These data indicate that this approach could be used to identify previously unreported sex-biased differences in miR expression and that a miR identified with this approach, miR548am-5p, can account for sex-dependent differences observed in the susceptibility to mitochondrial apoptosis of human DFs.

        来源:Current oncology , 2019

        作者:R. Hekkenberg;D. Sivajohanathan;T. P. Hanna;等

        关键词:Mohs;mms;...

        使用许可:Unknown

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        ObjectiveThe purpose of the present work was to develop evidence-based indications for Mohs micrographic surgery in patients with a diagnosis of skin cancer. MethodsThe guideline was developed by Cancer Care Ontario’s Program in Evidence-Based Care, together with the Melanoma Disease Site Group and the Surgical Oncology Program, through a systematic review of relevant literature, patient- and caregiver-specific consultation, and internal and external reviews. Recommendation 1Given a lack of high-quality, comparative evidence, surgery (with postoperative or intraoperative margin assessment) or radiation (for those who are ineligible for surgery) should remain the standard of care for patients with skin cancer. Recommendation 2Mohs micrographic surgery is recommended for patients with histologically confirmed recurrent basal cell carcinoma of the face and is appropriate for primary basal cell carcinomas of the face that are larger than 1 cm, have aggressive histology, or are located on the H zone of the face. Recommendation 3Mohs micrographic surgery should be performed by physicians who have completed a degree in medicine or equivalent, including a Royal College of Physicians and Surgeons of Canada Specialist Certificate or equivalent, and have received advanced training in Mohs micrographic surgery.

          来源:Ecology and Evolution , 2019

          作者:William J. Zielinski, Keith M. Slauson

          关键词:carnivore;denning;...

          使用许可:Unknown

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          来源:Parasites & Vectors , 2019

          作者:Xiao-Qiang Yu;Juan Wu;Xiao-yan Jiang;等

          关键词:Aedes aegypti;ATP-binding protein;...

          使用许可:CC BY

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          BackgroundBacillus thuringiensis israelensis (Bti) is a widely used mosquitocidal microbial pesticide due to its high toxicity. ATP-binding proteins (ABP) are prevalently detected in insects and are related to reaction against Bti toxins. However, the function of ABP in mosquito biocontrol is little known, especially in Aedes aegypti. Therefore, this study aimed to clarify the function of ABP in Ae. aegypti against Bti toxin.ResultsAedes aegypti ABP (GenBank: XM_001661856.2) was cloned, expressed and purified in this study. Far-western blotting and ELISA were also carried out to confirm the interaction between ABP and Cry11Aa. A bioassay of Cry11Aa was performed both in the presence and absence of ABP, which showed that the mortality of Ae. aegypti is increased with an increase in ABP.ConclusionsOur results suggest that ABP in Ae. aegypti can modulate the toxicity of Cry11Aa toxin to mosquitoes by binding to Bti toxin. This could not only enrich the mechanism of Bt toxin, but also provide more data for the biocontrol of this transmission vector.