Influence of Atomic Relaxations on the Moiré Flat Band Wave Functions in Antiparallel Twisted Bilayer WS2.

Twisting bilayers of transition metal dichalcogenides gives rise to a moiré potential resulting in flat bands with localized wave functions and enhanced correlation effects. In this work, scanning tunneling microscopy is used to image a WS2 bilayer twisted approximately 3° off the antiparallel alignment. Scanning tunneling spectroscopy reveals localized states in the vicinity of the valence band onset, which is observed to occur first in regions with S-on-S Bernal stacking. In contrast, density functional theory calculations on twisted bilayers that have been relaxed in vacuum predict the highest-lying flat valence band to be localized in regions of AA' stacking. However, agreement with experiment is recovered when the calculations are performed on bilayers in which the atomic displacements from the unrelaxed positions have been reduced, reflecting the influence of the substrate and finite temperature. This demonstrates the delicate interplay of atomic relaxations and the electronic structure of twisted bilayer materials.

Hydration Thermodynamics of Familial Parkinson's Disease-Linked Mutants of α-Synuclein.

The hydration thermodynamics of different mutants of α-synuclein (α-syn) related to familial Parkinson's disease (PD) is explored using a computational approach that combines both molecular dynamics simulations in water and integral equation theory of molecular liquids. This analysis focuses on the change in conformational entropy, hydration free energy (HFE), and partial molar volume of α-syn upon mutation. The results show that A53T, A30P, E46K, and H50Q mutants aggregate more readily and display increased HFE and less negative interaction volume than the wild-type α-syn. In contrast, an opposite trend is observed for the G51D mutant with a lower experimental aggregation rate. The residuewise decomposition analysis of the HFE highlights that the dehydration/hydration of the hydrophilic residue-rich N- and C-termini of α-syn majorly contributes to the change upon mutation. The hydration shell contributions of different residues to the interaction volume are consistent with its increase/decrease upon mutation. This work shows that both HFE and interaction volume determine the aggregation kinetics of α-syn upon mutation and may serve as an appropriate benchmark for the treatment of PD.

Hydration Thermodynamics of the N-Terminal FAD Mutants of Amyloid-ß.

The hydration thermodynamics of amyloid-ß (Aß) and its pathogenic familial Alzheimer's disease (FAD) mutants such as A2V, Taiwan (D7H), Tottori (D7N), and English (H6R) and the protective A2T mutant is investigated by a combination of all-atom, explicit water molecular dynamics (MD) simulations and the three-dimensional reference interaction site model (3D-RISM) theory. The change in the hydration free energy on mutation is decomposed into the energetic and entropic components, which comprise electrostatic and nonelectrostatic contributions. An increase in the hydration free energy is observed for A2V, D7H, D7N, and H6R mutations that increase the aggregation propensity of Aß and lead to an early onset of Alzheimer's disease, while a reverse trend is noted for the protective A2T mutation. An antiphase correlation is found between the change in the hydration energy and the internal energy of Aß upon mutation. A residue-wise decomposition analysis shows that the change in the hydration free energy of Aß on mutation is primarily due to the hydration/dehydration of the side-chain atoms of the negatively charged residues. The decrease in the hydration of the negatively charged residues on mutation may decrease the solubility of the mutant, which increases the observed aggregation propensity of the FAD mutants. Results obtained from the theory show an excellent match with the experimentally reported data.

Unconventional superconductivity at mesoscopic point contacts on the 3D Dirac semimetal Cd3As2.

Three-dimensional (3D) Dirac semimetals exist close to topological phase boundaries which, in principle, should make it possible to drive them into exotic new phases, such as topological superconductivity, by breaking certain symmetries. A practical realization of this idea has, however, hitherto been lacking. Here we show that the mesoscopic point contacts between pure silver (Ag) and the 3D Dirac semimetal Cd3As2 (ref. ) exhibit unconventional superconductivity with a critical temperature (onset) greater than 6 K whereas neither Cd3As2 nor Ag are superconductors. A gap amplitude of 6.5 meV is measured spectroscopically in this phase that varies weakly with temperature and survives up to a remarkably high temperature of 13 K, indicating the presence of a robust normal-state pseudogap. The observations indicate the emergence of a new unconventional superconducting phase that exists in a quantum mechanically confined region under a point contact between a Dirac semimetal and a normal metal.

Underuse of risk assessment and overuse of computed tomography pulmonary angiography in patients with suspected pulmonary thromboembolism.

BACKGROUND: Evidence suggests the potential overuse of computed tomography pulmonary angiography (CTPA) in patients with suspected pulmonary thromboembolism (PTE) in the absence of consistent use of pre-test clinical prediction rules and D-dimer assays. AIM: To evaluate use and diagnostic utility of clinical prediction rules and D-dimer assay in patients with suspected PTE and quantify potentially avoidable overuse of CTPA in low risk patients. METHODS: A total of 344 consecutive patients undergoing CTPA at a tertiary hospital was studied with regards to the use of D-dimer assays and clinical prediction rules for PTE. For each patient, a modified Wells score (mWS), revised Geneva score and PISA model were calculated retrospectively; performance characteristics for each rule for PTE were determined with reference to results of CTPA. Results for the mWS and D-dimer assays (when performed) were used to estimate the overuse of CTPA according to risk category. RESULTS: Use of a clinical prediction rule was documented in only 5.0% of cases. Of 269 low-risk patients who had a calculated mWS ≤4, only 64 (23.8%) had a D-dimer assay performed, with 30 (11.1%) having a PTE on CTPA. Among 75 patients with an mWS >4, 23 (30.7%) had a PTE on CTPA (P < 0.001). Compared to other prediction rules, an mWS>4 had the highest positive predictive value (31.0%) for PTE; all rules demonstrated similar negative predictive values for low-risk scores (87-89%). After adjusting for an 11% false negative rate for PTE in patients with low-risk mWS, overuse of CTPA was reported in up to 190 (55.2%) patients. CONCLUSION: More than 50% of patients with suspected PTE may be subject to unwarranted use of CTPA in the absence of pre-test clinical prediction rules coupled with D-dimer assays.

Self-oriented ß-crystalline phase in the polyvinylidene fluoride ferroelectric and piezo-sensitive ultrathin Langmuir-Schaefer film.

We report on the direct observation of ferroelectric switching and piezoelectric behaviour in ultrathin polyvinylidene fluoride (PVDF) films prepared by horizontal Langmuir-Schaefer (LS) technique. We have prepared pure ß-phase by just increasing the number of LS layers without using additional non-ferroelectric assisting agents. Edge-on oriented CH2-CF2 units of PVDF at the air-water interface enable self-orientation of ferroelectric dipoles by means of the hydrogen bonding network. Such restricted conformation of PVDF at the air-water interface results in an increased net dipole moment with the number of LS layers. The film's ferroelectric switching and piezoelectric sensitivity are demonstrated by hysteretic polarization switching loops and butterfly-loops, respectively. Successful circular domain writing on ultrathin LS film, down to 5 monolayers of PVDF, is demonstrated. The achievement of pure ß-phase of PVDF at room temperature without using any assisting agents may be promising for non-volatile memory and piezoelectric-based, ultrathin smart sensor devices.

Aiming to be NEAT: safely improving and sustaining access to emergency care in a tertiary referral hospital.

OBJECTIVE: To implement and evaluate strategies for improving access to emergency department (ED) care in a tertiary hospital. METHODS: A retrospective pre-post intervention study using routinely collected data involving all patients presenting acutely to the ED of a major tertiary hospital over a 2-year period. Main outcome measures were changes in: the percentage of patients exiting the ED (all patients, patients discharged directly from the ED, patients admitted to inpatient wards); mean patient transit times in the ED; inpatient mortality rates; rates of ED 'did not wait' and re-presentations within 48 h of ED discharge; and selected safety indicators. Qualitative data on staff perceptions of interventions were also gathered. RESULTS: Working groups focused on ED internal processes, ED-inpatient unit interface, hospital-wide discharge processes and performance monitoring and feedback. Twenty-five different reforms were enacted over a 9-month period from April to December 2012. Comparing the baseline period (January-March 2012) with the post-reform period (January-March 2013), the percentage of patients exiting the ED within 4 h rose for all patients presenting to the ED (from 32% to 62%), for patients discharged directly from the ED (from 41% to 75%) and for admitted patients (from 12% to 32%; P<0.001 for all comparisons). The mean (±s.d.) time all patients spent in the ED was reduced from 7.2±5.8 to 4.4±3.5 h (P<0.001) and, for admitted patients, was associated with reduced in-hospital mortality (from 2.3% to 1.7%; P=0.045). The 'did not wait' rates in ED fell from 6.9% to 1.9% (P<0.001), whereas ED re-presentations within 48 h among patients discharged from the ED rose slightly (from 3.1% to 3.8%; P=0.023). Improvements in outcome measures were maintained over the subsequent 12 months. CONCLUSIONS: Multiple reforms targeting processes both within the ED and its interface with inpatient units greatly improved access to ED care over 12 months and were associated with decreased in-hospital mortality. WHAT IS KNOWN ABOUT THIS TOPIC?: Prolonged stays in the ED result in overcrowding, delayed ambulance access to ED care and increased adverse outcomes for admitted patients. The introduction in Australia of National Emergency Access Targets (NEAT), which stipulate at least 70% of patients in the ED must exit the department within 4h, have spurred hospitals into implementing a wide range of reforms with varying levels of success in achieving such targets. WHAT DOES THIS PAPER ADD?: This study demonstrates how multiple reforms implemented in a poor performing tertiary hospital caused the proportion of patients exiting the ED within 4h to double within 9 months to reach levels comparable with best performing peer hospitals. This was associated with a 26% reduction in in-hospital mortality for admitted patients and no clinically significant adverse effects. It demonstrates the importance of robust governance structures, executive sponsorship, cross-disciplinary collaboration, regular feedback of NEAT performance data and major redesign of existing clinical processes, work practices and bed management operations. WHAT ARE THE IMPLICATIONS FOR CLINICIANS AND MANAGERS?: Improving access to emergency care should be regarded as a problem located and resolved both within and without the ED. It requires a whole-of-hospital solution involving interdisciplinary collaboration and significant change in culture and practice relating to inpatient units and their interface with the ED.

The Quest for High-Temperature Superconductivity in Nickelates under Ambient Pressure.

Recently, superconductivity with Tc ≈ 80 K was discovered in La3Ni2O7 under extreme hydrostatic pressure (>14 GPa). For practical applications, we needed to stabilize this state at ambient pressure. It was proposed that this could be accomplished by substituting La with Ba. To put this hypothesis to the test, we used the state-of-the-art atomic-layer-by-layer molecular beam epitaxy (ALL-MBE) technique to synthesize (La1-xBax)3Ni2O7 films, varying x and the distribution of La (lanthanum) and Ba (barium). Regrettably, none of the compositions we explored could be stabilized epitaxially; the targeted compounds decomposed immediately into a mixture of other phases. So, this path to high-temperature superconductivity in nickelates at ambient pressure does not seem promising.

Ferroelectric Switching at Symmetry-Broken Interfaces by Local Control of Dislocations Networks.

Semiconducting ferroelectric materials with low energy polarization switching offer a platform for next-generation electronics such as ferroelectric field-effect transistors. Recently discovered interfacial ferroelectricity in bilayers of transition metal dichalcogenide films provides an opportunity to combine the potential of semiconducting ferroelectrics with the design flexibility of 2D material devices. Here, local control of ferroelectric domains in a marginally twisted WS2 bilayer is demonstrated with a scanning tunneling microscope at room temperature, and their observed reversible evolution is understood using a string-like model of the domain wall network (DWN). Two characteristic regimes of DWN evolution are identified: (i) elastic bending of partial screw dislocations separating smaller domains with twin stackings due to mutual sliding of monolayers at domain boundaries and (ii) merging of primary domain walls into perfect screw dislocations, which become the seeds for the recovery of the initial domain structure upon reversing electric field. These results open the possibility to achieve full control over atomically thin semiconducting ferroelectric domains using local electric fields, which is a critical step towards their technological use.

Assessing the DNA structural integrity via selective annihilation of Watson-Crick hydrogen bonds: Insights from molecular dynamics simulations.

Understanding the role of base pairing and stacking displayed by polynucleotide chains interwind together resulting in a double-helical B-DNA type structure is crucial to gaining access to the sophisticated structural arrangement of DNA. Several computational and experimental studies hinted towards the dominance of base pairing over stacking for duplex stability. To find out how significant the individual Watson-Crick hydrogen bonds are in maintaining the double-helical integrity of the DNA, in the present article, we selectively switched off the hydrogen bonds (one specific bond or their combinations in all the base pairs at a time) via manipulating the force fields for A-T and G-C base pairs. We studied 12 systems in total via all-atom explicit-solvent molecular dynamics simulations (200 ns each). The MD output structures were compared with the control system by means of structural, dynamic, and energetic properties to monitor the overall consequences of removing H-bond(s) on the B-DNA characteristics of the model systems. Our findings suggest that all the individual hydrogen bonds involved in base pairing are vital for maintaining the DNA structural integrity as any possible alteration in Watson-Crick hydrogen bond(s) leads to the disintegration/collapse of DNA strands resulting in unfolded states.

Evidence for higher order topology in Bi and Bi0.92Sb0.08.

Higher order topological insulators (HOTIs) are a new class of topological materials which host protected states at the corners or hinges of a crystal. HOTIs provide an intriguing alternative platform for helical and chiral edge states and Majorana modes, but there are very few known materials in this class. Recent studies have proposed Bi as a potential HOTI, however, its topological classification is not yet well accepted. In this work, we show that the (110) facets of Bi and BiSb alloys can be used to unequivocally establish the topology of these systems. Bi and Bi0.92Sb0.08 (110) films were grown on silicon substrates using molecular beam epitaxy and studied by scanning tunneling spectroscopy. The surfaces manifest rectangular islands which show localized hinge states on three out of the four edges, consistent with the theory for the HOTI phase. This establishes Bi and Bi0.92Sb0.08 as HOTIs, and raises questions about the topological classification of the full family of BixSb1-x alloys.

Effect of Alzheimer's Disease Causative and Protective Mutations on the Hydration Environment of Amyloid-ß.

This study investigates the local structure and dynamics of hydration water around the intrinsically disordered protein amyloid-ß (Aß) and its Alzheimer's disease causative N-terminus mutants, i.e., A2V, Taiwan (D7H), Tottori (D7N), and English (H6R), and the protective A2T mutant via atomistic MD simulations. The effect of mutations on the hydration environment around different domains of this protein is evaluated through the surface distribution function, tetrahedral order parameter, and the survival probability of the water molecules within the hydration shell. The water density around the hydrophobic hp1 (17-21) domain is found to be higher for the A2T mutant as compared to the wild-type Aß and its selected causative mutants. The average tetrahedral order parameter of water molecules around the hydrophobic hp1 (17-21) domain shows that water molecules are less ordered around the A2V, Taiwan, Tottori, and English mutants and more ordered around the A2T mutant than those of the wild-type protein. The survival probability decays rapidly for the A2V, Taiwan, Tottori, and English mutants, while it is comparatively slower for the protective A2T mutant. These results exhibit different hydration environments for the causative and protective mutants highlighting the differential roles of charge and hydrophobicity.

Interaction Volume Is a Measure of the Aggregation Propensity of Amyloid-ß.

This study highlights the significance of the partial molar volume of amino acids in predicting the aggregation propensity of an intrinsically disordered protein, amyloid-ß (Aß), and its mutants in aqueous solution. The change in the interaction volume of the protein or mutant is quantitatively correlated with its calculated experimental aggregation propensity. This method also reveals how the interaction volume may be tuned by changing the charge and hydrophobicity of Aß. While a positive change in the interaction volume and a higher aggregation propensity are observed for mutants with a decrease in the overall charge and/or an increase in hydrophobicity, a reverse trend is observed for the mutants with a decrease in the hydrophobicity and/or an increase in its charge. Hence, the interaction volume may be considered as a key parameter for monitoring protein aggregation that bridges the gap between the experimental aggregation kinetics and solvation thermodynamics.

Tip-induced superconductivity coexisting with preserved topological properties in line-nodal semimetal ZrSiS.

ZrSiS was recently shown to be a new material with topologically non-trivial band structure that exhibits multiple Dirac nodes and a robust linear band dispersion up to an unusually high energy of 2 eV. Such a robust linear dispersion makes the topological properties of ZrSiS insensitive to perturbations like carrier doping or lattice distortion. Here, we show that a novel superconducting phase with a remarkably high [Formula: see text] of 7.5 K can be induced in single crystals of ZrSiS by a non-superconducting metallic tip of Ag. From first-principles calculations, we show that the observed superconducting phase might originate from a dramatic enhancement of density of states due to the presence of a metallic tip on ZrSiS. Our calculations also show that the emerging tip-induced superconducting phase co-exists with the well preserved topological properties of ZrSiS.

Hydration Water Distribution around Intrinsically Disordered Proteins.

The distribution and local structural order of hydration water in the proximity of intrinsically disordered proteins/regions are investigated within the frame work of three-dimensional (3D)-reference interaction site model theory. The hydration water distribution around the protein surface is quantified in terms of the 3D distribution function and the water-protein radial distribution function (RDF), whereas the local ordering of water molecules around the protein surface is measured in terms of the tetrahedral order parameter. To the best of our knowledge, this is the first theoretical study of the 3D hydration water distribution profiles of disordered proteins. The analysis of the 3D hydration profiles reveals a nonuniform distribution and higher hydration water density around disordered proteins as compared to the globular ones because of their noncompact structures with more solvent-accessible surface area and the abundance of charged residues. This difference is also evident in the residue-specific RDFs of water around different polar and nonpolar atoms of charged and hydrophobic residues of the globular and disordered proteins. The average tetrahedral order parameter evaluated as a function of the water-water distance shows that water molecules are more ordered around disordered regions/proteins because of their higher mean net charge facilitating stronger water-protein interactions.

Received care compared to ADP-guided care of patients admitted to hospital with chest pain of possible cardiac origin.

PURPOSE: To assess the extent to which accelerated diagnostic protocols (ADPs), compared to traditional care, identify patients presenting to emergency departments (EDs) with chest pain who are at low cardiac risk and eligible for early ED discharge. PATIENTS AND METHODS: Retrospective study of 290 patients admitted to hospital for further evaluation of chest pain following negative ED workup (no acute ischemic electrocardiogram [ECG] changes or elevation of initial serum troponin assay). Demographic data, serial ECG and troponin results, Thrombolysis in Myocardial Infarction (TIMI) score, cardiac investigations, and outcomes (confirmed acute coronary syndrome [ACS] at discharge and major adverse cardiac events [MACEs]) over 6 months of follow-up were analyzed. A validated ADP (ADAPT-ADP) was retrospectively applied to the cohort, and processes and outcomes of ADP-guided care were compared with those of care actually received. RESULTS: Patients had mean (±SD) TIMI score of 1.8 (±1.7); six (2.0%) patients were diagnosed with ACS at discharge. At 6 months, one patient (0.3%) re-presented with ACS and two (0.6%) died of non-coronary causes. The ADAPT-ADP defined 97 (33.4%) patients as being at low risk and eligible for early ED discharge, but who instead incurred mean hospital stay of 1.5 days, with 40.2% in telemetry beds, and 21.6% subject to non-invasive testing with only one positive result for coronary artery disease. None had a discharge diagnosis of ACS or developed MACE at 6 months. CONCLUSION: Compared to traditional care, application of the ADAPT-ADP would have allowed one-third of chest pain patients with initially negative investigations in ED to have been safely discharged from ED.

Comparison of nine coronary risk scores in evaluating patients presenting to hospital with undifferentiated chest pain.

INTRODUCTION: We compared performance of nine risk scores for coronary heart disease (CHD) among patients presenting to an emergency department (ED) with undifferentiated chest pain of possible coronary origin. METHODS: A retrospective study was undertaken of adult patients presenting with chest pain to atertiary hospital ED with no electrocardiographs or troponin results diagnostic of ischemic chest pain (ICP) or acute coronary syndrome at ED presentation, and no clearly evident noncoronary diagnosis. Risk scores were applied using cut-points distinguishing low- from high-risk patients according to discharge diagnosis of noncardiac chest pain (NCCP) or ICP, respectively. A lower odds ratio (OR) for ICP denoted lower risk for ICP. Score performance was compared using area under receiver-operator characteristic curves (AUC) and predictive values. RESULTS: A total of 401 patients were studied, of whom 123 (30.7%) had ICP as final diagnosis. Among the nine risk scores, those with greatest ability to detect low-risk patients were The North American Chest Pain Rule (NACPR) score (OR=0.35, 95% CI=0.27-0.46); History, ECG, Age, Risk Factors, and Troponin (HEART) score (OR=0.43; 95% CI=0.35-0.52); and Thrombolysis in Myocardial Infarction (TIMI) score (OR=0.49; 95% CI=0.41-0.58). Discrimination between patients with NCCP and those with ICP was greatest for HEART score (AUC=0.82; 95% CI=0.78-0.86) and lowest for Accelerated Diagnostic Protocol to Assess Patients with Chest Pain Symptoms Using Contemporary Troponins (ADAPT) score (AUC=0.63; 95% CI=0.58-0.69). In excluding ICP, ADAPT had negative predictive value (NPV) 100% (miss rate 0%) but classified only 1.7% of patients as low risk, compared to NACPR with NPV 98% (miss rate 2%), classifying 10.2% as low risk, and HEART with NPV 94% (miss rate 6%), classifying 32.4% as low risk. CONCLUSION: The NACPR risk score maximized yield of low-risk patients with lowest miss rate for ICP, while HEART score classified highest proportion of low-risk patients but with a higher miss rate.

Mesoscopic superconductivity and high spin polarization coexisting at metallic point contacts on Weyl semimetal TaAs.

A Weyl semimetal is a topologically non-trivial phase of matter that hosts mass-less Weyl fermions, the particles that remained elusive for more than 80 years since their theoretical discovery. The Weyl semimetals exhibit unique transport properties and remarkably high surface spin polarization. Here we show that a mesoscopic superconducting phase with critical temperature Tc=7 K can be realized by forming metallic point contacts with silver (Ag) on single crystals of TaAs, while neither Ag nor TaAs are superconductors. Andreev reflection spectroscopy of such point contacts reveals a superconducting gap of 1.2 meV that coexists with a high transport spin polarization of 60% indicating a highly spin-polarized supercurrent flowing through the point contacts on TaAs. Therefore, apart from the discovery of a novel mesoscopic superconducting phase, our results also show that the point contacts on Weyl semimetals are potentially important for applications in spintronics.

One-pot sequential alkynylation and cycloaddition: regioselective construction and biological evaluation of novel benzoxazole-triazole derivatives.

Individually, benzoxazole and triazole moieties are of significant biological interest owing to their importance in drugs and pharmaceuticals. To assess their combined biological impact when woven into one molecule, we designed a novel, regioselective, multicomponent, one-pot (MCOP) approach for the construction of benzoxazole-linked triazoles. The synthesis has been achieved in two sequential steps involving copper-catalyzed alkynylation of benzoxazole followed by a 1,3-dipolar cycloaddition reaction. By combination of these two bioactive units into one core, a series of new benzoxazole-triazole scaffolds has been synthesized and subjected to in vitro antibacterial and anticancer evaluation. Tests against clinical isolates of Staphylococcus aureus and Escherichia coli showed potent Gram-negative activity for compounds 4{1,1,1}, 4{1,1,4}, and 4{1,2,1}. The cytotoxicity of the synthesized library was determined against three cancer cell lines: HeLa, SKBr3, and Hep G2. Compound 4{2,2,2} showed significant cytotoxicity against all the cell lines. These preliminary bioassay evaluations strongly suggest the promise and scope of these novel molecules as therapeutic agents in medical science.

Evaluation and outcomes of patients admitted to a tertiary medical assessment unit with acute chest pain of possible coronary origin.

OBJECTIVES: The study aims to (i) profile clinical characteristics, risk estimates of acute coronary syndrome (ACS), use and yield of non-invasive cardiac testing, discharge diagnosis and 30-day outcomes among patients admitted with acute chest pain of possible coronary origin; and (ii) construct a risk stratification algorithm that informs management decisions. METHODS: This is a retrospective cohort study of 130 consecutive patients admitted to a tertiary hospital medical assessment unit between 24 January and 22 March 2012. Estimates of ACS risk were based on Australian guidelines and Thrombolysis in Myocardial Infarction (TIMI) scores. RESULTS: Patients were of mean age 61 years, 45% had known coronary artery disease (CAD), 58% presented with typical ischaemic pain, 82% had intermediate to high ACS risk and 61% underwent testing. Myocardial ischaemia was cardiologist-confirmed discharge diagnosis in 29% of patients, and was associated with known CAD, typical pain, multiple risk factors and high TIMI risk scores (P < 0.001 for all associations). Of 98 non-invasive investigations, 9% (95% CI, 5-17%) were positive for myocardial ischaemia. Major adverse event rate at 30 days was 0.8% (95% CI, <0.1-6%). An algorithm was constructed that integrates known CAD, ACS risk and TIMI scores in identifying low-risk patients capable of rapid discharge from EDs without further investigation, and classifying the remainder into risk groups that informs choice of investigations and need for telemetry. CONCLUSIONS: In patients with indeterminate chest pain, clinical features and risk scores identify most with myocardial ischaemia. An algorithm is presented that might inform triaging, early discharge, choice of testing and need for telemetry.