There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Background and Purpose—The authors present an overview of the current evidence and management recommendations for evaluation and treatment of adults with acute ischemic stroke. The intended audienc...

/pdf/guidelines-for-the-early-management-of-patients-with-acute-19udbft6e7.pdf

Guidelines for the Early Management of Patients With Acute Ischemic Stroke A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

Objective To determine the effects of antiplatelet therapy among patients at high risk of occlusive vascular events. Design Collaborative meta-analyses (systematic overviews). Inclusion criteria Randomised trials of an antiplatelet regimen versus control or of one antiplatelet regimen versus another in high risk patients (with acute or previous vascular disease or some other predisposing condition) from which results were available before September 1997. Trials had to use a method of randomisation that precluded prior knowledge of the next treatment to be allocated and comparisons had to be unconfounded-that is, have study groups that differed only in terms of antiplatelet regimen. Studies reviewed 287 studies involving 135 000 patients in comparisons of antiplatelet therapy versus control and 77 000 in comparisons of different antiplatelet regimens. Main outcome measure "Serious vascular event": non-fatal myocardial infarction, non-fatal stroke, or vascular death. Results Overall, among these High risk patients, allocation to antiplatelet therapy reduced the combined outcome of any serious vascular event by about one quarter; non-fatal myocardial infarction was reduced by one third, non-fatal stroke by one quarter, and vascular mortality by one sixth (with no apparent adverse effect on other deaths). Absolute reductions in the risk of having a serious vascular event were 36 (SE 5) per 1000 treated for two years among patients with previous myocardial infarction; 38 (5) per 1000 patients treated for one month among patients with acute myocardial infarction; 36 (6) per 1000 treated for two years among those with previous stroke or transient ischaemic attack; 9 (3) per 1000 treated for three weeks among those with acute stroke; and 22 (3) per 1000 treated for two years among other high risk patients (with separately significant results for those with stable angina (P=0.0005), peripheral arterial disease (P=0.004), and atrial fibrillation (P=0.01)). In each of these high risk categories, the absolute benefits substantially outweighed the absolute risks of major extracranial bleeding. Aspirin was the most widely studied antiplatelet drug, with doses of 75-150 mg daily at least as effective as higher daily doses. The effects of doses lower than 75 mg daily were less certain. Clopidogrel reduced serious vascular events by 10% (4%) compared with aspirin, which was similar to the 12% (7%) reduction observed with its analogue ticlopidine. Addition of dipyridamole to aspirin produced no significant further reduction in vascular events compared with aspirin alone. Among patients at high risk of immediate coronary occlusion, short term addition of an intravenous glycoprotein IIb/IIIa antagonist to aspirin prevented a further 20 (4) vascular events per 1000 (P <0.0001) but caused 23 major (but rarely fatal) extracranial bleeds per 1000. Conclusions Aspirin (or another oral antiplatelet drug) is protective in most types of patient at increased risk of occlusive vascular events, including those with an acute myocardial infarction or ischaemic stroke, unstable or stable angina, previous myocardial infarction, stroke or cerebral ischaemia, peripheral arterial disease, or atrial fibrillation, Low dose aspirin (75-150 mg daily) is an effective antiplatelet regimen for long term use, but in acute settings an initial loading dose of at least 150 mg aspirin may be required. Adding a second antiplatelet drug to aspirin may produce additional benefits in some clinical circumstances, but more research into this strategy is needed.

/pdf/collaborative-meta-analysis-of-randomised-trials-of-8dyu3duelv.pdf

Collaborative meta-analysis of randomised trials of antiplatelet therapy for prevention of death, myocardial infarction, and stroke in high risk patients

This is an updated version of supplementary information to accompany "Quantum supremacy using a programmable superconducting processor", an article published in the October 24, 2019 issue of Nature. The main article is freely available at this https URL. Summary of changes since arXiv:1910.11333v1 (submitted 23 Oct 2019): added URL for qFlex source code; added Erratum section; added Figure S41 comparing statistical and total uncertainty for log and linear XEB; new References [1,65]; miscellaneous updates for clarity and style consistency; miscellaneous typographical and formatting corrections.

/pdf/supplementary-information-for-quantum-supremacy-using-a-3tkhfafpzk.pdf

Supplementary information for "Quantum supremacy using a programmable superconducting processor"

https://www.chpso.org/sites/main/files/file-attachments/chest-2008-geerts-381s-453s.pdf

Prevention of Venous Thromboembolism* American College of Chest Physicians Evidence- Based Clinical Practice Guidelines (8th Edition)

This study deals with photonic crystal fiber designed to have a zero dispersion wavelength, lambda0 close to 715 nm. A picosecond titanium-sapphire laser pumps the fibre to produce single mode pair-photons at 583 nm signal and 900 nm idler wavelength. The pairs can be collected and detected with lumped efficiencies through 10 nm interference filters up to 24% in the signal channel and 14% in the idler channel. The brightness required for multiphoton experiments can be reached with only milliwatts of pump power. This paper reports on the progress of a fibre heralded source of 1550 nm single photons relevant for quantum cryptography.

Fibre pair photon sources for quantum information

We have shown that four-wave mixing in micro-structured fibres can be a versatile source of photon pairs for quantum optics experiments. I will review the progress towards all fibre sources for various quantum information applications.

Quantum optics in micro-structured fibers

We present a silicon-on-insulator quantum photonic device able to generate and analyze two maximally entangled qubits. Quantum interference between resonant four-wave mixing sources, phase-stable frequency-selection, and quantum state tomography are shown.

On-chip generation and analysis of maximal path-frequency entanglement

We describe fabrication methods for making nano-cavities in pure diamond centered around light emitting color centers. We will present results showing how nearby structures change the emission and spin properties.

Tailoring single photon emission from diamond using nano-structures

Optical quantum technologies require new photonic components to exploit integrated architecture. We demonstrate quantum interference in MMI couplers and coupled waveguides that implement two-particle quantum walks, showing unique quantum behaviour.

/pdf/new-photonic-components-for-quantum-information-science-1f7llxyvbf.pdf

Jeremy L. O'Brien

Papers

Fibre pair photon sources for quantum information

Quantum optics in micro-structured fibers

On-chip generation and analysis of maximal path-frequency entanglement

Tailoring single photon emission from diamond using nano-structures

New photonic components for quantum information science