2,730 research outputs found

    Recursive relations for a quiver gauge theory

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    We study the recursive relations for a quiver gauge theory with the gauge group SU(N1)×SU(N2)SU(N_1)\times SU(N_2) with bifundamental fermions transforming as (N1,N2ˉ)(N_1,\bar{N_2}). We work out the recursive relation for the amplitudes involving a pair of quark and antiquark and gluons of each gauge group. We realize directly in the recursive relations the invariance under the order preserving permutations of the gluons of the first and the second gauge group. We check the proposed relations for MHV, 6-point and 7-point amplitudes and find the agreements with the known results and the known relations with the single gauge group amplitudes. The proposed recursive relation is much more efficient in calculating the amplitudes than using the known relations with the amplitudes of the single gauge group.Comment: 33 pages and 2 figures, minor correction

    Design of a ferrite rod antenna for harvesting energy from medium wave broadcast signals

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    Radio frequency (RF) energy harvesting is an emerging technology that has the potential to eliminate the need for batteries and reduce maintenance costs of sensing applications. The antenna is one of the critical components that determines its performance and while antenna design has been well researched for the purpose of communication, the design for RF energy harvesting applications has not been widely addressed. The authors present an optimised design for such an antenna for harvesting energy from medium wave broadcast transmissions. They derive and use a model for computing the optimal antenna configuration given application requirements on output voltage and power, material costs and physical dimensions. Design requirements for powering autonomous smart meters have been considered. The proposed approach was used to obtain the antenna configuration that is able to deliver 1 mW of power to 1 kΩ load at a distance of up to 9 km, sufficient to replace batteries on low-power sensing applications. Measurements using a prototype device have been used to verify the authors simulations

    Parametric sensitivity analysis of the separation process for n-butanol production

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    n-butanol and iso-butanol are commonly produced by the hydrogenation of n-butyraldehyde and iso-butyraldehyde employing the patented copper catalyst accommodated in the reactors in series. The main cause of the lower n-butanol and iso-butanol yield was due to the catalyst blockage rendering a pressure build-up that could lead to a plant shut down. Bypassing the last reactor from the series could be a potential solution to continue running the plant until the next shutdown plan to replace catalyst. The study adopted simulation approach using Aspen Plus V10 to investigate the effect of bypassing the last reactor in the series to the product purity of the downstream separation processes. The iso-butanol and n-butanol with the desired purity were produced from the distillate and bottom product when the column was operated at the RR of 8.03 and DF of 0.328. The reaction conversion of R-102 was varied from 0.1-0.995 but the variation did not significantly change the composition of the main product. Hence, the present study affirmed that the bypassing of third reactor from the reactor train would not affect the product purity of the main product, n-butanol

    Pediatric Midface Fractures: Outcomes and Complications of 218 Patients

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    Objective To analyze management, outcomes, and complications of pediatric midface fractures. Methods Retrospective cohort study at an urban, single‐institution, multispecialty surgical teams, at two level 1 pediatric trauma centers. Query included subjects aged 0–17 diagnosed with midface fractures between 2012 and 2016. Results A total of 218 pediatric patients presented with 410 total midface fractures. The most common etiologies included motor vehicle collisions (MVC) (n = 56, 25.7%), sport‐related (n = 35, 16.1%), and assault/battery (n = 32, 14.7%). Fracture site distribution included: 125 maxillary (34 with exclusively the nasal/frontal process), 109 nasal, 47 ethmoid, 40 sphenoid, 33 zygoma, 29 frontal sinus, 21 lacrimal, and 6 palatal. Among these, there were 105 orbital, 17 naso‐orbito‐ethmoid, and 12 Le Fort fractures. One‐quarter of patients received at least one midface‐related operation during the initial encounter. Operative intervention rates for specific midface fracture subsites were not significantly different (X2 = 6.827, P = .234). One hundred thirty‐five patients (63.4%) attended follow‐up, thus known complication rate was 14.6% (n = 31). Complication rates between midface fracture subsites were not significantly different (X2 = 5.629, P = .229). Complications included facial deformity (n = 18), nasal airway obstruction (n = 8), diplopia (n = 4), hardware‐related pain (n = 3), and paresthesias (n = 3). Conclusions The most common sites of pediatric midface fractures involved the maxilla, and nasal bones. Three quarters of pediatric midface fractures were treated conservatively, with low rates of complications. Facial deformity was the most common complication; as such, proper management and follow‐up are important to ensure normal growth and development of the pediatric facial skeleton. Level of Evidence

    Spatial Regulation of ABCG25, an ABA Exporter, Is an Important Component of the Mechanism Controlling Cellular ABA Levels

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    The phytohormone abscisic acid (ABA) plays crucial roles in various physiological processes, including responses to abiotic stresses, in plants. Recently, multiple ABA transporters were identified. The loss-of-function and gain-of-function mutants of these transporters show altered ABA sensitivity and stomata regulation, highlighting the importance of ABA transporters in ABA-mediated processes. However, how the activity of these transporters is regulated remains elusive. Here, we show that spatial regulation of ATP BINDING CASETTE G25 (ABCG25), an ABA exporter, is an important mechanism controlling its activity. ABCG25, as a soluble green fluorescent protein (sGFP) fusion, was subject to posttranslational regulation via clathrin-dependent and adaptor protein complex-2-dependent endocytosis followed by trafficking to the vacuole. The levels of sGFP: ABCG25 at the plasma membrane (PM) were regulated by abiotic stresses and exogenously applied ABA; PM-localized sGFP: ABCG25 decreased under abiotic stress conditions via activation of endocytosis in an ABA-independent manner, but increased upon application of exogenous ABA via activation of recycling from early endosomes in an ABA-dependent manner. Based on these findings, we propose that the spatial regulation of ABCG25 is an important component of the mechanism by which plants fine-tune cellular ABA levels according to cellular and environmental conditions.1197Ysciescopu

    Mechanical thrombectomy: can it be safely delivered out of hours in the UK?

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    BACKGROUND: Mechanical thrombectomy was approved by NICE as a treatment for stroke in 2016. However, most of the evidence is from studies conducted during working hours. Only few centres in the UK perform thrombectomies out-of-hours. The Royal Stoke University Hospital (RSUH) has offered thrombectomies over 24 h (24/7) since 2010. The aim of this service review is to compare the outcomes for patients treated in regular working hours to those treated outside normal working hours within this unit. METHODS: This retrospective service analysis includes all patients treated with mechanical thrombectomy at RSUH since the start of the service in January 2010 to June 2019. Data on key demographics, timings, procedural complications, and long-term outcomes including death and disability at 90 days were collected. In-hours was defined as the time between 8:00-17:00 h, Monday to Friday; out-of-hours was defined as any time outside this period. RESULTS: In total, 516 mechanical thrombectomies were performed in this time period; data were available on 501 of these. Successful recanalization (TICI 2b/3) was achieved in 86% of patients. By 90 days 96 (19%) had died and 234 (47%) were functionally independent (modified Rankin Scale score ≀ 2). 211 (42%) of the procedures were performed in-hours and 290 (58%) out-of-hours. Door-to-CT and door-to-groin times were significantly longer out-of-hours than in-hours, but thrombectomy duration was significantly shorter. There were no significant differences in complications and short- and long-term outcomes. CONCLUSION: Mechanical thrombectomy was delivered safely and effectively 24/7 in this UK hospital, with no difference in clinical outcomes

    Anterolateral thigh osteomyocutaneous femur (ALTO) flap reconstruction for composite mandible and near total tongue defect utilizing a retrograde intramedullary femoral nail stabilization technique: Report of a first case

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    The anterior lateral thigh osteomyocutaneous free flap (ALTO) offers the advantage of reconstructing large bony and soft tissue defects. We report a novel approach for femur stabilization via retrograde intramedullary nail placement in a patient with a near total tongue and large mandibular defect who underwent ALTO reconstruction that saves operating room time and decreases risk of post-operative fracture

    Two-proton small-angle correlations in central heavy-ion collisions: a beam-energy and system-size dependent study

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    Small-angle correlations of pairs of protons emitted in central collisions of Ca + Ca, Ru + Ru and Au + Au at beam energies from 400 to 1500 MeV per nucleon are investigated with the FOPI detector system at SIS/GSI Darmstadt. Dependences on system size and beam energy are presented which extend the experimental data basis of pp correlations in the SIS energy range substantially. The size of the proton-emitting source is estimated by comparing the experimental data with the output of a final-state interaction model which utilizes either static Gaussian sources or the one-body phase-space distribution of protons provided by the BUU transport approach. The trends in the experimental data, i.e. system-size and beam energy dependences, are well reproduced by this hybrid model. However, the pp correlation function is found rather insensitive to the stiffness of the equation of state entering the transport model calculations.Comment: 9 pages, 8 figures, accepted at Eur. Phys. Journ.

    Isospin dependence of relative yields of K+K^+ and K0K^0 mesons at 1.528 AGeV

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    Results on K+K^+ and K0K^0 meson production in 4496^{96}_{44}Ru + 4496^{96}_{44}Ru and 4096^{96}_{40}Zr + 4096^{96}_{40}Zr collisions at a beam kinetic energy of 1.528AA GeV, measured with the FOPI detector at GSI-Darmstadt, are investigated as a possible probe of isospin effects in high density nuclear matter. The measured double ratio (K+/K0K^+/K^0)Ru_{Ru}/(K+/K0K^+/K^0)Zr_{Zr} is compared to the predictions of a thermal model and a Relativistic Mean Field transport model using two different collision scenarios and under different assumptions on the stiffness of the symmetry energy. We find a good agreement with the thermal model prediction and the assumption of a soft symmetry energy for infinite nuclear matter while more realistic transport simulations of the collisions show a similar agreement with the data but also exhibit a reduced sensitivity to the symmetry term.Comment: 5 pages, 3 figures. accepted for publication in Phys. Rev.

    Strange meson production in Al+Al collisions at 1.9A GeV

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    The production of K+^+, K−^- and φ\varphi(1020) mesons is studied in Al+Al collisions at a beam energy of 1.9A GeV which is close or below the production threshold in NN reactions. Inverse slopes, anisotropy parameters, and total emission yields of K±^{\pm} mesons are obtained. A comparison of the ratio of kinetic energy distributions of K−^- and K+^+ mesons to the HSD transport model calculations suggests that the inclusion of the in-medium modifications of kaon properties is necessary to reproduce the ratio. The inverse slope and total yield of ϕ\phi mesons are deduced. The contribution to K−^- production from ϕ\phi meson decays is found to be [17 ±\pm 3 (stat) −7+2^{+2}_{-7} (syst)] %. The results are in line with previous K±^{\pm} and ϕ\phi data obtained for different colliding systems at similar incident beam energies.Comment: 16 pages, 11 figure
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