5,198 research outputs found
Reference invasive tests of microvascular injury in myocardial infarction
No abstract available
A life long song of resilience: in pursuit of Abraham Hagholm
Life of Abraham Hagholm (1811-1890), collector of Swedish folkmusic and schol teacher. Music as an agent of physical strength, character and social stature
Simulating Quantum Dynamics On A Quantum Computer
We present efficient quantum algorithms for simulating time-dependent
Hamiltonian evolution of general input states using an oracular model of a
quantum computer. Our algorithms use either constant or adaptively chosen time
steps and are significant because they are the first to have time-complexities
that are comparable to the best known methods for simulating time-independent
Hamiltonian evolution, given appropriate smoothness criteria on the Hamiltonian
are satisfied. We provide a thorough cost analysis of these algorithms that
considers discretizion errors in both the time and the representation of the
Hamiltonian. In addition, we provide the first upper bounds for the error in
Lie-Trotter-Suzuki approximations to unitary evolution operators, that use
adaptively chosen time steps.Comment: Paper modified from previous version to enhance clarity. Comments are
welcom
Nineteenth Century Constitutional Amendment in Maine
The state of Maine has had but one constitution in its one hundred and forty-four year existence. The document itself, however, has been amended nearly one hundred times. Thirty of these amendments came before the close of the nineteenth century; most of the subsequent amendments were either suggested initially before the turn of the present century or owe their existence to an amendment approved prior to 1900. What is proposed in this study is an examination of the amendments with particular emphasis upon the conflicting reasons of proponents and opponents of specific measures. This study will attempt to evaluate the necessity and the efficacy of successful alterations of the constitution. It will also attempt to suggest certain trends in the power accorded the three branches of the state government and in the changing role and responsibilities of the electorate. In strictly numerical terms elections, election procedure, and the franchise far outrank any of the other classes of amendments. Some of these were proposed to meet immediate exigencies; others to clarify, simplify or democratize the system of elections and the franchise; a few to restrict the right to vote. The power balance in the state government forms the second major class of amendments. These alterations illustrate the changing positions among the three branches of the government and the electorate. Other noteworthy constitutional changes involved apportionment, debt limitation, taxation, special legislation, and prohibition. All of the amendments are not of equal importance and the space devoted to each is certainly not an infallible guide to their relative importance. Certain successful amendments were proposed many times; others infrequently; still others just a single time. The reasons for a detailed amendment may be simple and just the opposite. Appendices A through H offer a summary of legislative action on amendments throughout the nineteenth century. The above is tempered with the realization that any attempt at historical explanation must deal with failure as well as success and thus a discussion of unsuccessful proposals is an integral part of this study
Immediate access arteriovenous grafts versus tunnelled central venous catheters: study protocol for a randomised controlled trial
Background
Autologous arteriovenous fistulae (AVF) are the optimal form of vascular access for haemodialysis. AVFs typically require 6 to 8 weeks to “mature” from the time of surgery before they can be cannulated. Patients with end-stage renal disease needing urgent vascular access therefore traditionally require insertion of a tunnelled central venous catheter (TCVC). TCVCs are associated with high infection rates and central venous stenosis.
Early cannulation synthetic arteriovenous grafts (ecAVG) provide a novel alternative to TCVCs, permitting rapid access to the bloodstream and immediate needling for haemodialysis. Published rates of infection in small series are low.
The aim of this study is to compare whether TCVC ± AVF or ecAVG ± AVF provide a better strategy for managing patients requiring immediate vascular access for haemodialysis.
Methods/design
This is a prospective randomised controlled trial comparing the strategy of TCVC ± AVF to ecAVG ± AVF. Patients requiring urgent vascular access will receive a study information sheet and written consent will be obtained. Patients will be randomised to receive either: (i) TCVC (and native AVF if this is anatomically possible) or (ii) ecAVG (± AVF).
118 patients will be recruited. The primary outcome is systemic bacteraemia at 6Â months. Secondary outcomes include culture-proven bacteraemia rates at 1Â year and 2Â years; primary and secondary patency rates at 3, 6, 12 and 24Â months; stenoses; re-intervention rates; re-admission rate; mortality and quality of life. Additionally, treatment delays, impact on service provision and cost-effectiveness will be evaluated.
Discussion
This is the first randomised controlled trial comparing TCVC to ecAVG for patients requiring urgent vascular access for haemodialysis. The complications of TCVC are considered an unfortunate necessity in patients requiring urgent haemodialysis who do not have autologous vascular access. If this study demonstrates that ecAVGs provide a safe and practical alternative to TCVC, this could instigate a paradigm shift in nephrology thinking and access planning.</p
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