94 research outputs found

    Intermolecular 1,3-dipolar cycloadditions of muchnones with acetylenic dipolarophiles: Sorting out the regioselectivity

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    A series of 1,3-dipolar cycloadditions of munchnones with acetylenic dipolarophiles was studied, wherein factors related to regioselectivity were investigated. The results from munchnones with electronically divergent thioaryl substituents compared with others bearing alkyl substituents suggest that an unsymmetrical transition state structure, rather than FMO perturbation, plays a significant role in regioselection. If eclipsing interactions preclude a highly unsymmetrical transition state however, then minimizing steric interactions becomes important. A pair of complementarily substituted munchnones, differing only in the position of isotopic labels, establishes an inherently symmetrical electronic nature of the mesoionic heterocycle.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31644/1/0000578.pd

    Physical Activity Levels in U.S. Latino/Hispanic Adults

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    Physical activity (PA) prevalence among U.S. Latino/Hispanic adults of diverse backgrounds is not well known. This study describes PA among a representative sample of U.S. Latino/Hispanic adults

    The effects of beta-blockers on dobutamine-atropine stress echocardiography: early protocol versus standard protocol

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    BACKGROUND: To study the effects of Beta-blockers during Dobutamine Stress Echocardiography (DSE) comparing the hemodynamic benefits of an early administration of atropine in patients taking or not Beta-blockers. METHODS: One hundred and twenty-one patients were submitted to dobutamine stress echocardiography for the investigation of myocardial ischemia. The administration of atropine was randomized into two groups: A or B (early protocol when atropine was administered at 10 and 20 mcg/kg/min of dobutamine, respectively) and C (standard protocol with atropine at 40 mcg/kg/min of dobutamine). Analysis of the effects of Beta-blockers was done regarding the behavior pattern of heart rate and blood pressure, test time, number of conclusive and inconclusive (negative sub-maximum test) results, total doses of atropine and dobutamine, and general complications. RESULTS: Beta-blocked patients who received early atropine (Group A&B) had a significantly lower double product (p = 0.008), a higher mean test time (p = 0.010) and required a higher dose of atropine (p = 0.0005) when compared to the patients in this group who were not Beta-blocked. The same findings occurred in the standard protocol (Group C), however the early administration of atropine reduced test time both in the presence and absence of this therapy (p = 0.0001). The patients with Beta-blockers in Group A&B had a lower rate of inconclusive tests (26%) compared to those in Group C (40%). Complications were similar in both groups. CONCLUSION: The chronotropic response during dobutamine stress echocardiography was significantly reduced with the use of Beta-blockers. The early administration of atropine optimized the hemodynamic response, reduced test time in patients with or without Beta-blockers and reduced the number of inconclusive tests in the early protocol

    Commissioning of the vacuum system of the KATRIN Main Spectrometer

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    The KATRIN experiment will probe the neutrino mass by measuring the beta-electron energy spectrum near the endpoint of tritium beta-decay. An integral energy analysis will be performed by an electro-static spectrometer (Main Spectrometer), an ultra-high vacuum vessel with a length of 23.2 m, a volume of 1240 m^3, and a complex inner electrode system with about 120000 individual parts. The strong magnetic field that guides the beta-electrons is provided by super-conducting solenoids at both ends of the spectrometer. Its influence on turbo-molecular pumps and vacuum gauges had to be considered. A system consisting of 6 turbo-molecular pumps and 3 km of non-evaporable getter strips has been deployed and was tested during the commissioning of the spectrometer. In this paper the configuration, the commissioning with bake-out at 300{\deg}C, and the performance of this system are presented in detail. The vacuum system has to maintain a pressure in the 10^{-11} mbar range. It is demonstrated that the performance of the system is already close to these stringent functional requirements for the KATRIN experiment, which will start at the end of 2016.Comment: submitted for publication in JINST, 39 pages, 15 figure

    The PHENIX Experiment at RHIC

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    The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix

    SARS-CoV-2 receptor binding domain displayed on HBsAg virus–like particles elicits protective immunity in macaques

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    Authorized vaccines against SARS-CoV-2 remain less available in low- and middle-income countries due to insufficient supply, high costs, and storage requirements. Global immunity could still benefit from new vaccines using widely available, safe adjuvants, such as alum and protein subunits, suited to low-cost production in existing manufacturing facilities. Here, a clinical-stage vaccine candidate comprising a SARS-CoV-2 receptor binding domain–hepatitis B surface antigen virus–like particle elicited protective immunity in cynomolgus macaques. Titers of neutralizing antibodies (>104) induced by this candidate were above the range of protection for other licensed vaccines in nonhuman primates. Including CpG 1018 did not significantly improve the immunological responses. Vaccinated animals challenged with SARS-CoV-2 showed reduced median viral loads in bronchoalveolar lavage (~3.4 log10) and nasal mucosa (~2.9 log10) versus sham controls. These data support the potential benefit of this design for a low-cost modular vaccine platform for SARS-CoV-2 and other variants of concern or betacoronaviruses

    Real-world experience of nintedanib for progressive fibrosing interstitial lung disease in the UK

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    Background Nintedanib slows progression of lung function decline in patients with progressive fibrosing (PF) interstitial lung disease (ILD) and was recommended for this indication within the United Kingdom (UK) National Health Service in Scotland in June 2021 and in England, Wales and Northern Ireland in November 2021. To date, there has been no national evaluation of the use of nintedanib for PF-ILD in a real-world setting.Methods 26 UK centres were invited to take part in a national service evaluation between 17 November 2021 and 30 September 2022. Summary data regarding underlying diagnosis, pulmonary function tests, diagnostic criteria, radiological appearance, concurrent immunosuppressive therapy and drug tolerability were collected via electronic survey.Results 24 UK prescribing centres responded to the service evaluation invitation. Between 17 November 2021 and 30 September 2022, 1120 patients received a multidisciplinary team recommendation to commence nintedanib for PF-ILD. The most common underlying diagnoses were hypersensitivity pneumonitis (298 out of 1120, 26.6%), connective tissue disease associated ILD (197 out of 1120, 17.6%), rheumatoid arthritis associated ILD (180 out of 1120, 16.0%), idiopathic nonspecific interstitial pneumonia (125 out of 1120, 11.1%) and unclassifiable ILD (100 out of 1120, 8.9%). Of these, 54.4% (609 out of 1120) were receiving concomitant corticosteroids, 355 (31.7%) out of 1120 were receiving concomitant mycophenolate mofetil and 340 (30.3%) out of 1120 were receiving another immunosuppressive/modulatory therapy. Radiological progression of ILD combined with worsening respiratory symptoms was the most common reason for the diagnosis of PF-ILD.Conclusion We have demonstrated the use of nintedanib for the treatment of PF-ILD across a broad range of underlying conditions. Nintedanib is frequently co-prescribed alongside immunosuppressive and immunomodulatory therapy. The use of nintedanib for the treatment of PF-ILD has demonstrated acceptable tolerability in a real-world setting

    Improved Upper Limit on the Neutrino Mass from a Direct Kinematic Method by KATRIN

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    We report on the neutrino mass measurement result from the first four-week science run of the Karlsruhe Tritium Neutrino experiment KATRIN in spring 2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are energy analyzed by a high-resolution MAC-E filter. A fit of the integrated electron spectrum over a narrow interval around the kinematic end point at 18.57 keV gives an effective neutrino mass square value of (1.01.1+0.9)eV2(−1.0^{+0.9}_{−1.1}) eV^2. From this, we derive an upper limit of 1.1 eV (90% confidence level) on the absolute mass scale of neutrinos. This value coincides with the KATRIN sensitivity. It improves upon previous mass limits from kinematic measurements by almost a factor of 2 and provides model-independent input to cosmological studies of structure formation
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