2,018 research outputs found

    The NASA-UC-UH Eta-Earth Program: IV. A Low-mass Planet Orbiting an M Dwarf 3.6 PC from Earth

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    We report the discovery of a low-mass planet orbiting Gl 15 A based on radial velocities from the Eta-Earth Survey using HIRES at Keck Observatory. Gl 15 Ab is a planet with minimum mass Msini = 5.35 ±\pm 0.75 M_\oplus, orbital period P = 11.4433 ±\pm 0.0016 days, and an orbit that is consistent with circular. We characterize the host star using a variety of techniques. Photometric observations at Fairborn Observatory show no evidence for rotational modulation of spots at the orbital period to a limit of ~0.1 mmag, thus supporting the existence of the planet. We detect a second RV signal with a period of 44 days that we attribute to rotational modulation of stellar surface features, as confirmed by optical photometry and the Ca II H & K activity indicator. Using infrared spectroscopy from Palomar-TripleSpec, we measure an M2 V spectral type and a sub-solar metallicity ([M/H] = -0.22, [Fe/H] = -0.32). We measure a stellar radius of 0.3863 ±\pm 0.0021 R_\odot based on interferometry from CHARA.Comment: ApJ accepted, 11 pages, 8 figures, 3 table

    Atomic Layer-controlled Nonlinear Terahertz Valleytronics in Dirac Semi-metal and Semiconductor PtSe2

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    Platinum diselenide (PtSe2) is a promising two-dimensional (2D) material for the terahertz (THz) range as, unlike other transition metal dichalcogenides (TMDs), its bandgap can be uniquely tuned from a semiconductor in the near-infrared to a semimetal with the number of atomic layers. This gives the material unique THz photonic properties that can be layer-engineered. Here, we demonstrate that a controlled THz nonlinearity - tuned from monolayer to bulk PtSe2 - can be realised in wafer size polycrystalline PtSe2 through the generation of ultrafast photocurrents and the engineering of the bandstructure valleys. This is combined with the PtSe2 layer interaction with the substrate for a broken material centro-symmetry permitting a second order nonlinearity. Further, we show layer-dependent circular dichroism, where the sign of the ultrafast currents and hence the phase of the emitted THz pulse can be controlled through the excitation of different bandstructure valleys. In particular, we show that a semimetal has a strong dichroism that is absent in the monolayer and few layer semiconducting limit. The microscopic origins of this TMD bandstructure engineering is highlighted through detailed DFT simulations and show that circular dichroism can be controlled when PtSe2 becomes a semimetal and when the K-valleys can be excited. As well as showing that PtSe2 is a promising material for THz generation through layer controlled optical nonlinearities, this work opens up new class of circular dichroism materials beyond the monolayer limit that has been the case of traditional TMDs, and impacting a range of domains from THz valleytronics, THz spintronics to harmonic generation

    Molecular Diversity and Gene Evolution of the Venom Arsenal of Terebridae Predatory Marine Snails

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    Venom peptides from predatory organisms are a resource for investigating evolutionary processes such as adaptive radiation or diversification, and exemplify promising targets for biomedical drug development. Terebridae are an understudied lineage of conoidean snails,which also includes cone snails and turrids. Characterization of cone snail venompeptides, conotoxins, has revealed a cocktail of bioactive compounds used to investigate physiological cellular function, predator-prey interactions, and to develop novel therapeutics. However, venom diversity of other conoidean snails remains poorly understood. The present research applies a venomics approach to characterize novel terebrid venom peptides, teretoxins, from the venom gland transcriptomes of Triplostephanus anilis and Terebra subulata. Next-generation sequencing and de novo assembly identified 139 putative teretoxins that were analyzed for the presence of canonical peptide features as identified in conotoxins. To meet the challenges of de novo assembly, multiple approaches for cross validation of findings were performed to achieve reliable assemblies of venom duct transcriptomes and to obtain a robust portrait of Terebridae venom. Phylogenetic methodology was used to identify 14 teretoxin gene superfamilies for the first time, 13 of which are unique to the Terebridae. Additionally, basic local algorithm search tool homologybased searches to venom-related genes and posttranslational modification enzymes identified a convergence of certain venom proteins, suchas actinoporin, commonly foundinvenoms. This research provides novel insights intovenomevolutionandrecruitment in Conoidean predatory marine snails and identifies a plethora of terebrid venom peptides that can be used to investigate fundamental questions pertaining to gene evolution

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    <i>TESS</i> Spots a Compact System of Super-Earths around the Naked-eye Star HR 858

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    Transiting Exoplanet Survey Satellite (TESS) observations have revealed a compact multiplanet system around the sixth-magnitude star HR 858 (TIC 178155732, TOI 396), located 32 pc away. Three planets, each about twice the size of Earth, transit this slightly evolved, late F-type star, which is also a member of a visual binary. Two of the planets may be in mean motion resonance. We analyze the TESS observations, using novel methods to model and remove instrumental systematic errors, and combine these data with follow-up observations taken from a suite of ground-based telescopes to characterize the planetary system. The HR 858 planets are enticing targets for precise radial velocity observations, secondary eclipse spectroscopy, and measurements of the Rossiter–McLaughlin effect

    Systemic AAV vectors for widespread and targeted gene delivery in rodents

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    We recently developed adeno-associated virus (AAV) capsids to facilitate efficient and noninvasive gene transfer to the central and peripheral nervous systems. However, a detailed protocol for generating and systemically delivering novel AAV variants was not previously available. In this protocol, we describe how to produce and intravenously administer AAVs to adult mice to specifically label and/or genetically manipulate cells in the nervous system and organs, including the heart. The procedure comprises three separate stages: AAV production, intravenous delivery, and evaluation of transgene expression. The protocol spans 8 d, excluding the time required to assess gene expression, and can be readily adopted by researchers with basic molecular biology, cell culture, and animal work experience. We provide guidelines for experimental design and choice of the capsid, cargo, and viral dose appropriate for the experimental aims. The procedures outlined here are adaptable to diverse biomedical applications, from anatomical and functional mapping to gene expression, silencing, and editing

    Thrombocytopenia and platelet transfusions in ICU patients: an international inception cohort study (PLOT-ICU)

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    Purpose Thrombocytopenia (platelet count < 150 × 109/L) is common in intensive care unit (ICU) patients and is likely associated with worse outcomes. In this study we present international contemporary data on thrombocytopenia in ICU patients. Methods We conducted a prospective cohort study in adult ICU patients in 52 ICUs across 10 countries. We assessed frequencies of thrombocytopenia, use of platelet transfusions and clinical outcomes including mortality. We evaluated pre-selected potential risk factors for the development of thrombocytopenia during ICU stay and associations between thrombocytopenia at ICU admission and 90-day mortality using pre-specified logistic regression analyses. Results We analysed 1166 ICU patients; the median age was 63 years and 39.5% were female. Overall, 43.2% (95% confidence interval (CI) 40.4–46.1) had thrombocytopenia; 23.4% (20–26) had thrombocytopenia at ICU admission, and 19.8% (17.6–22.2) developed thrombocytopenia during their ICU stay. Non-AIDS-, non-cancer-related immune deficiency, liver failure, male sex, septic shock, and bleeding at ICU admission were associated with the development of thrombocytopenia during ICU stay. Among patients with thrombocytopenia, 22.6% received platelet transfusion(s), and 64.3% of in-ICU transfusions were prophylactic. Patients with thrombocytopenia had higher occurrences of bleeding and death, fewer days alive without the use of life-support, and fewer days alive and out of hospital. Thrombocytopenia at ICU admission was associated with 90-day mortality (adjusted odds ratio 1.7; 95% CI 1.19–2.42). Conclusion Thrombocytopenia occurred in 43% of critically ill patients and was associated with worse outcomes including increased mortality. Platelet transfusions were given to 23% of patients with thrombocytopenia and most were prophylactic.publishedVersio

    Cost-Effectiveness Modeling of Surgery Plus Adjuvant Endocrine Therapy Versus Primary Endocrine Therapy Alone in UK Women Aged 70 and Over With Early Breast Cancer

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    Objectives: Approximately 20% of UK women aged 70+ with early breast cancer receive primary endocrine therapy (PET) instead of surgery. PET reduces surgical morbidity but with some survival decrement. To complement and utilize a treatment dependent prognostic model, we investigated the cost-effectiveness of surgery plus adjuvant therapies versus PET for women with varying health and fitness, identifying subgroups for which each treatment is cost-effective. Methods: Survival outcomes from a statistical model, and published data on recurrence, were combined with data from a large, multicenter, prospective cohort study of over 3400 UK women aged 70+ with early breast cancer and median 52-month follow-up, to populate a probabilistic economic model. This model evaluated the cost-effectiveness of surgery plus adjuvant therapies relative to PET for 24 illustrative subgroups: Age {70, 80, 90} × Nodal status {FALSE (F), TRUE (T)} × Comorbidity score {0, 1, 2, 3+}. Results: For a 70-year-old with no lymph node involvement and no comorbidities (70, F, 0), surgery plus adjuvant therapies was cheaper and more effective than PET. For other subgroups, surgery plus adjuvant therapies was more effective but more expensive. Surgery plus adjuvant therapies was not cost-effective for 4 of the 24 subgroups: (90, F, 2), (90, F, 3), (90, T, 2), (90, T, 3). Conclusion: From a UK perspective, surgery plus adjuvant therapies is clinically effective and cost-effective for most women aged 70+ with early breast cancer. Cost-effectiveness reduces with age and comorbidities, and for women over 90 with multiple comorbidities, there is little cost benefit and a negative impact on quality of life

    Oral Abstracts 7: RA ClinicalO37. Long-Term Outcomes of Early RA Patients Initiated with Adalimumab Plus Methotrexate Compared with Methotrexate Alone Following a Targeted Treatment Approach

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    Background: This analysis assessed, on a group level, whether there is a long-term advantage for early RA patients treated with adalimumab (ADA) + MTX vs those initially treated with placebo (PBO) + MTX who either responded to therapy or added ADA following inadequate response (IR). Methods: OPTIMA was a 78- week, randomized, controlled trial of ADA + MTX vs PBO + MTX in MTX-naïve early (<1 year) RA patients. Therapy was adjusted at week 26: ADA + MTX-responders (R) who achieved DAS28 (CRP) <3.2 at weeks 22 and 26 (Period 1, P1) were re-randomized to withdraw or continue ADA and PBO + MTX-R continued randomized therapy for 52 weeks (P2); IR-patients received open-label (OL) ADA + MTX during P2. This post hoc analysis evaluated the proportion of patients at week 78 with DAS28 (CRP) <3.2, HAQ-DI <0.5, and/or ΔmTSS ≤0.5 by initial treatment. To account for patients who withdrew ADA during P2, an equivalent proportion of R was imputed from ADA + MTX-R patients. Results: At week 26, significantly more patients had low disease activity, normal function, and/or no radiographic progression with ADA + MTX vs PBO + MTX (Table 1). Differences in clinical and functional outcomes disappeared following additional treatment, when PBO + MTX-IR (n = 348/460) switched to OL ADA + MTX. Addition of OL ADA slowed radiographic progression, but more patients who received ADA + MTX from baseline had no radiographic progression at week 78 than patients who received initial PBO + MTX. Conclusions: Early RA patients treated with PBO + MTX achieved comparable long-term clinical and functional outcomes on a group level as those who began ADA + MTX, but only when therapy was optimized by the addition of ADA in PBO + MTX-IR. Still, ADA + MTX therapy conferred a radiographic benefit although the difference did not appear to translate to an additional functional benefit. Disclosures: P.E., AbbVie, Merck, Pfizer, UCB, Roche, BMS—Provided Expert Advice, Undertaken Trials, AbbVie—AbbVie sponsored the study, contributed to its design, and participated in the collection, analysis, and interpretation of the data, and in the writing, reviewing, and approval of the final version. R.F., AbbVie, Pfizer, Merck, Roche, UCB, Celgene, Amgen, AstraZeneca, BMS, Janssen, Lilly, Novartis—Research Grants, Consultation Fees. S.F., AbbVie—Employee, Stocks. A.K., AbbVie, Amgen, AstraZeneca, BMS, Celgene, Centocor-Janssen, Pfizer, Roche, UCB—Research Grants, Consultation Fees. H.K., AbbVie—Employee, Stocks. S.R., AbbVie—Employee, Stocks. J.S., AbbVie, Amgen, AstraZeneca, BMS, Celgene, Centocor-Janssen, GlaxoSmithKline, Lilly, Pfizer (Wyeth), MSD (Schering-Plough), Novo-Nordisk, Roche, Sandoz, UCB—Research Grants, Consultation Fees. R.V., AbbVie, BMS, GlaxoSmithKline, Human Genome Sciences, Merck, Pfizer, Roche, UCB Pharma—Consultation Fees, Research Support. Table 1.Week 78 clinical, functional, and radiographic outcomes in patients who received continued ADA + MTX vs those who continued PBO + MTX or added open-label ADA following an inadequate response ADA + MTX, n/N (%)a PBO + MTX, n/N (%)b Outcome Week 26 Week 52 Week 78 Week 26 Week 52 Week 78 DAS28 (CRP) <3.2 246/466 (53) 304/465 (65) 303/465 (65) 139/460 (30)*** 284/460 (62) 300/460 (65) HAQ-DI <0.5 211/466 (45) 220/466 (47) 224/466 (48) 150/460 (33)*** 203/460 (44) 208/460 (45) ΔmTSS ≤0.5 402/462 (87) 379/445 (86) 382/443 (86) 330/459 (72)*** 318/440 (72)*** 318/440 (72)*** DAS28 (CRP) <3.2 + ΔmTSS ≤0.5 216/462 (47) 260/443 (59) 266/443 (60) 112/459 (24)*** 196/440 (45) 211/440 (48)*** DAS28 (CRP) <3.2 + HAQ-DI <0.5 + ΔmTSS ≤0.5 146/462 (32) 168/443 (38) 174/443 (39) 82/459 (18)*** 120/440 (27)*** 135/440 (31)** aIncludes patients from the ADA Continuation (n = 105) and OL ADA Carry On (n = 259) arms, as well as the proportional equivalent number of responders from the ADA Withdrawal arm (n = 102). bIncludes patients from the MTX Continuation (n = 112) and Rescue ADA (n = 348) arms. Last observation carried forward: DAS28 (CRP) and HAQ-DI; Multiple imputations: ΔmTSS. ***P < 0.001 and **iP < 0.01, respectively, for differences between initial treatments from chi-squar

    International genome-wide meta-analysis identifies new primary biliary cirrhosis risk loci and targetable pathogenic pathways.

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    Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery data sets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4,261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5 × 10(-8)) and used pathway analysis to identify JAK-STAT/IL12/IL27 signalling and cytokine-cytokine pathways, for which relevant therapies exist
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