2,220 research outputs found

    Impact of varying degrees of renal dysfunction on transcatheter and surgical aortic valve replacement

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    BackgroundRenal impairment portends adverse outcomes in patients undergoing valvular heart surgery. The relationship between renal dysfunction in patients undergoing transcatheter aortic valve replacement (TAVR) is incompletely understood.MethodsA retrospective review of 1336 patients undergoing surgical aortic valve replacement (SAVR; 2002-2012) and 321 patients undergoing TAVR (2007-2012) was performed. Patients were divided into 3 glomerular filtration rate (GFR) groups: GFR greater than 60 mL/min, GFR 31 to 60 mL/min, and GFR 30 mL/min or less. Logistic and linear regression analysis was performed to estimate the TAVR effect on outcomes. Risk adjustments were made using the Society for Thoracic Surgeons (STS) predicted risk of mortality (PROM).ResultsTAVR patients were older (82 vs 65 years; P < .001), had a poorer ejection fraction (48% vs 53%; P < .001), were more likely female (45% vs 41%; P = .23), and had a higher STS PROM (11.9% vs 4.6%; P < .001). In-hospital mortality rates for TAVR and SAVR were 3.5% and 4.1%, respectively (P = .60), a result that marginally favors TAVR after risk adjustment (adjusted odds ratio = .52, P = .06). In SAVR patients, worsening preoperative renal failure was associated with increased in-hospital mortality (P = .004) and hospital (P < .001) and intensive care unit (ICU) (P < .001) lengths of stay. In contrast, worsening renal function did not influence in-hospital mortality (P = .78) and hospital (P < .23) and ICU (P = .88) lengths of stay in TAVR patients.ConclusionsWorsening renal function was associated with increased in-hospital mortality, hospital length of stay, and ICU length of stay in SAVR patients, but not in TAVR patients. This unexpected finding may have important clinical implications in patients with aortic stenosis and preoperative renal dysfunction

    Radiotherapy for marginally resected, unresectable or recurrent giant cell tumor of the bone: a rare cancer network study

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    The role of radiotherapy for local control of marginally resected, unresectable, and recurrent giant cell tumors of bone (GCToB) has not been well defined. The number of patients affected by this rare disease is low. We present a series of 58 patients with biopsy proven GCToB who were treated with radiation therapy. A retrospective review of the role of radiotherapy in the treatment of GCToB was conducted in participating institutions of the Rare Cancer Network. Eligibility criteria consisted of the use of radiotherapy for marginally resected, unresectable, and recurrent GCToB. Fifty-eight patients with biopsy proven GCToB were analyzed from 9 participating North American and European institutions. Forty-five patients had a primary tumor and 13 patients had a recurrent tumor. Median radiation dose was 50 Gy in a median of 25 fractions. Indication for radiation therapy was marginal resection in 33 patients, unresectable tumor in 13 patients, recurrence in 9 patients and palliation in 2 patients. Median tumor size was 7.0 cm. A significant proportion of the tumors involved critical structures. Median follow-up was 8.0 years. Five year local control was 85% . Of the 7 local failures, 3 were treated successfully with salvage surgery. All patients who received palliation achieved symptom relief. Five year overall survival was 94%. None of the patients experienced grade 3 or higher acute toxicity. This study reports a large published experience in the treatment of GCToB with radiotherapy. Radiotherapy can provide excellent local control for incompletely resected, unresectable or recurrent GCToB with acceptable morbidity

    Detection of ESKAPE bacterial pathogens at the point of care using isothermal DNA-based assays in a portable degas-actuated microfluidic diagnostic assay platform

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    An estimated 1.5 billion microbial infections occur globally each year and result in ~4.6 million deaths. A technology gap associated with commercially available diagnostic tests in remote and underdeveloped regions prevents timely pathogen identification for effective antibiotic chemotherapies for infected patients. The result is a trial-and-error approach that is limited in effectiveness, increases risk for patients while contributing to antimicrobial drug resistance, and reduces the lifetime of antibiotics. This paper addresses this important diagnostic technology gap by describing a low-cost, portable, rapid, and easy-to-use microfluidic cartridgebased system for detecting the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) bacterial pathogens that are most commonly associated with antibiotic resistance. The point-of-care molecular diagnostic system consists of a vacuumdegassed microfluidic cartridge preloaded with lyophilized recombinase polymerase amplification (RPA) assays and a small portable battery-powered electronic incubator/ reader. The isothermal RPA assays detect the targeted ESKAPE pathogens with high sensitivity (e.g., a limit of detection of ~10 nucleic acid molecules) that is comparable to that of current PCR-based assays, and they offer advantages in power consumption, engineering, and robustness, which are three critical elements required for the point-of-care setting

    Fluctuation-driven, topology-stabilized order in a correlated nodal semimetal

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    The interplay between strong electron correlation and band topology is at the forefront of condensed matter research. As a direct consequence of correlation, magnetism enriches topological phases and also has promising functional applications. However, the influence of topology on magnetism remains unclear, and the main research effort has been limited to ground state magnetic orders. Here we report a novel order above the magnetic transition temperature in magnetic Weyl semimetal (WSM) CeAlGe. Such order shows a number of anomalies in electrical and thermal transport, and neutron scattering measurements. We attribute this order to the coupling of Weyl fermions and magnetic fluctuations originating from a three-dimensional Seiberg-Witten monopole, which qualitatively agrees well with the observations. Our work reveals a prominent role topology may play in tailoring electron correlation beyond ground state ordering, and offers a new avenue to investigate emergent electronic properties in magnetic topological materials.Comment: 32 pages, 15 figure

    The effect of pure mitral regurgitation on mitral annular geometry and three-dimensional saddle shape

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    ObjectiveChronic ischemic mitral regurgitation is associated with mitral annular dilatation in the septal-lateral dimension and flattening of the annular 3-dimensional saddle shape. To examine whether these perturbations are caused by the ischemic insult, mitral regurgitation, or both, we investigated the effects of pure mitral regurgitation (low pressure volume overload) on annular geometry and shape.MethodsEight radiopaque markers were sutured evenly around the mitral annulus in sheep randomized to control (CTRL, n = 8) or experimental (HOLE, n = 12) groups. In HOLE, a 3.5- to 4.8-mm hole was punched in the posterior leaflet to generate pure mitral regurgitation. Four-dimensional marker coordinates were obtained radiographically 1 and 12 weeks postoperatively. Mitral annular area, annular septal-lateral and commissure–commissure dimensions, and annular height were calculated every 16.7 ms.ResultsMitral regurgitation grade was 0.4 ± 0.4 in CTRL and 3.0 ± 0.8 in HOLE (P < .001) at 12 weeks. End-diastolic left ventricular volume index was greater in HOLE at both 1 and 12 weeks; end-systolic volume index was larger in HOLE at 12 weeks. Mitral annular area increased in HOLE predominantly in the commissure–commissure dimension, with no difference in annular height between HOLE versus CTRL at 1 or 12 weeks, respectively.ConclusionIn contrast with annular septal-lateral dilatation and flattening of the annular saddle shape observed with chronic ischemic mitral regurgitation, pure mitral regurgitation was associated with commissure–commissure dimension annular dilatation and no change in annular shape. Thus, infarction is a more important determinant of septal-lateral dilatation and annular shape than mitral regurgitation, which reinforces the need for disease-specific designs of annuloplasty rings

    Looking towards the future: patient-specific computational modeling to optimize outcomes for transcatheter mitral valve repair

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    Severe mitral valve regurgitation (MR) is a heart valve disease that progresses to end-stage congestive heart failure and death if left untreated. Surgical repair or replacement of the mitral valve (MV) remains the gold standard for treatment of severe MR, with repair techniques aiming to restore the native geometry of the MV. However, patients with extensive co-morbidities may be ineligible for surgical intervention. With the emergence of transcatheter MV repair (TMVR) treatment paradigms for MR will evolve. The longer-term outcomes of TMVR and its effectiveness compared to surgical repair remain unknown given the differing patient eligibility for either treatment at this time. Advances in computational modeling will elucidate answers to these questions, employing techniques such as finite element method and fluid structure interactions. Use of clinical imaging will permit patient-specific MV models to be created with high accuracy and replicate MV pathophysiology. It is anticipated that TMVR technology will gradually expand to treat lower-risk patient groups, thus pre-procedural computational modeling will play a crucial role guiding clinicians towards the optimal intervention. Additionally, concerted efforts to create MV models will establish atlases of pathologies and biomechanics profiles which could delineate which patient populations would best benefit from specific surgical vs. TMVR options. In this review, we describe recent literature on MV computational modeling, its relevance to MV repair techniques, and future directions for translational application of computational modeling for treatment of MR

    Proceedings of the International Conference on Genetic Improvement of Sorghum and Pearl Millet

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    In 1971, an international symposium, Sorghum in the Seventies , organized by the All India Coordinated Sorghum Improvement Project with support from the Indian Council of Agricultural Research and the Rockefeller Foundation was held in Hyderabad, India. The symposium reviewed the current knowledge base of the scientific, production and nutritional aspects of sorghum as a crop and as a human food. In 1981, ICRISAT, INTSORMIL, and the Indian Council of Agricultural Research (ICAR) sponsored Sorghum in the Eighties , an international symposium at ICRISAT Center in India, to review the achievements accomplished in sorghum research during the preceding 10 years. They reviewed sorghum\u27s role as an important cereal food, feed, construction material, and fuel in the developed and developing countries. In 1994, after discussion among INTSORMIL and ICRISAT scientists, it was recognized that an international meeting on the genetic improvement of grain sorghum and pearl millet was needed and would be strongly supported by the international sorghum and millet research community. Those discussions led to the September 1996 International Conference on Genetic Improvement of Sorghum and Pearl Millet. Grain sorghum and pearl millet are major food grains in the semiarid tropics of Africa, India, and South America. Sorghum ranks fifth among the world\u27s cereals, following wheat, maize, rice, and barley. F AO includes all millets together in its production estimates. Current estimates indicate that annual world sorghum production is approximately 61 million metric tons and world millet production is approximately 20 million metric tons. The inaugural speaker of this 1996 conference, Dr. Leland House, indicated global population is projected to increase to nine billion people by the year 2030 and is projected to increase most rapidly in the developing world. This will create a growing demand for food, as well as potential new market opportunities for food products developed from these basic grains

    Science Impacts of the SPHEREx All-Sky Optical to Near-Infrared Spectral Survey: Report of a Community Workshop Examining Extragalactic, Galactic, Stellar and Planetary Science

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    SPHEREx is a proposed SMEX mission selected for Phase A. SPHEREx will carry out the first all-sky spectral survey and provide for every 6.2" pixel a spectra between 0.75 and 4.18 μ\mum [with R\sim41.4] and 4.18 and 5.00 μ\mum [with R\sim135]. The SPHEREx team has proposed three specific science investigations to be carried out with this unique data set: cosmic inflation, interstellar and circumstellar ices, and the extra-galactic background light. It is readily apparent, however, that many other questions in astrophysics and planetary sciences could be addressed with the SPHEREx data. The SPHEREx team convened a community workshop in February 2016, with the intent of enlisting the aid of a larger group of scientists in defining these questions. This paper summarizes the rich and varied menu of investigations that was laid out. It includes studies of the composition of main belt and Trojan/Greek asteroids; mapping the zodiacal light with unprecedented spatial and spectral resolution; identifying and studying very low-metallicity stars; improving stellar parameters in order to better characterize transiting exoplanets; studying aliphatic and aromatic carbon-bearing molecules in the interstellar medium; mapping star formation rates in nearby galaxies; determining the redshift of clusters of galaxies; identifying high redshift quasars over the full sky; and providing a NIR spectrum for most eROSITA X-ray sources. All of these investigations, and others not listed here, can be carried out with the nominal all-sky spectra to be produced by SPHEREx. In addition, the workshop defined enhanced data products and user tools which would facilitate some of these scientific studies. Finally, the workshop noted the high degrees of synergy between SPHEREx and a number of other current or forthcoming programs, including JWST, WFIRST, Euclid, GAIA, K2/Kepler, TESS, eROSITA and LSST.Comment: Report of the First SPHEREx Community Workshop, http://spherex.caltech.edu/Workshop.html , 84 pages, 28 figure
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