Accurate diagnosis of severe coronary stenosis based on resting magnetocardiography: a prospective, single-center, cross-sectional analysis

OBJECTIVE To evalu ate the role of resting magnetocardiography in identifying seve re coronary artery stenosis in patients with suspected coronary artery disease.METHODS A total of 513 patients with angina symptoms were included and divided into two groups based on the extent of coronary artery disease determined by angiography:the non-severe coronary stenusis group(<70% stenosis) and the severe coronary stenosis group(≥70% stenosis).The diagnostic model was constructed using magnetic field map(MFM) parameters,either individually or in combination with clinical indicators.The performance of the models was evaluated using receiver operating characteristic curves,accuracy,sensitivity,specificity,positive predictive value(PPV) and ne gative predictive value(NPV).Calibration plots and decision curve analysis were performed to investigate the clinical utility and performance of the models,respectively.RESULTS In the severe coronary stenosis group,QR_MCTDd,S_MDp,and TT_(MA)C_(50) were significantly higher than those in the non-severe coronary stenosis group(10,46±10.66 vs,5.11±6.07,P <0.001;7.2±8.64 vs.4.68±6.95,P=0.003;0.32±57.29 vs.0.26±57.29,P <0.001).While,QR_MV_(amp),R_(MA),and T_(MA) in the severe coronary stenosis group were lower(0.23±0.16 vs.0.28±0.16,P<0.001;55.06±48.68 vs.59.24±53.01,P<0.001;51.67±39.32 vs. 60.45±51.33,P <0.001).Seven MFM parameters were integrated into the model,resulting in an area under the curve of 0.810(95% CI:0.765-0.855).The sensitivity,specificity,PPV,NPV,and accurecy were 71.7%,80.4%,93.3%,42.8 %,and 73.5%;respectevely.The combined model exhibited an area under the curve of 0.845(95% CI:0.798-0.892).The sensitivity,specificity,PPV,NPV,and accuracy were 84.3%,73.8%,92.6%,54.6%,and 82.1%;respectively.Calibration curves demonstrate d excellent agreement between the nomogram prediction and actual observation.The decision curve analysis showed that the c ombine d model provided greater net benefit compared to the magnetocardingraphy model.CONCLUSIONS The novel quantitative MFM parameters,whether used individually or in combination with clinical indicators,have been shown to effectively pre dict the risk of severe coronary stenosis in patients presenting with angina-like symptoms.Magnetocardiography,an emerging non-invasive diagnostic tool,warrants further exploration for its potential in diagnosing coronary heart disease.

Electronic structure of single-crystalline graphene grown on Cu/Ni(111) alloy film

Graphene with a Dirac cone-like electronic structure has been extensively studied because of its novel transport properties and potential application for future electronic devices.For epitaxially grown graphene,the process conditions and the microstructures are strongly dependent on various substrate materials with different lattice constants and interface energies.Utilizing angle-resolved photoemission spectroscopy,here we report an investigation of the electronic structure of single-crystalline graphene grown on Cu/Ni(111)alloy film by chemical vapor deposition.With a relatively low growth temperature,graphene on Cu/Ni(111)exhibits a Dirac cone-like dispersion comparable to that of graphene grown on Cu(111).The linear dispersions forming Dirac cone are as wide as 2 e V,with the Fermi velocity of approximately 1.1×10^6 m/s.Dirac cone opens a gap of approximately 152 meV at the binding energy of approximately 304 meV.Our findings would promote the study of engineering of graphene on different substrate materials.

Flux-to-voltage characteristic simulation of superconducting nanowire interference device

Inspired by recent discoveries of the quasi-Josephson effect in shunted nanowire devices,we propose a superconducting nanowire interference device in this study,which is a combination of parallel ultrathin superconducting nanowires and a shunt resistor.A simple model based on the switching effect of nanowires and fluxoid quantization effect is developed to describe the behavior of the device.The current-voltage characteristic and flux-to-voltage conversion curves are simulated and discussed to verify the feasibility.Appropriate parameters of the shunt resistor and inductor are deduced for fabricating the devices.

Large-inductance superconducting microstrip photon detector enabling 10 photon-number resolution

Efficient and precise photon-number-resolving detectors are essential for optical quantum information science.Despite this,very few detectors have been able to distinguish photon numbers with both high fidelity and a large dynamic range,all while maintaining high speed and high timing precision.Superconducting nanostrip-based detectors excel at counting single photons efficiently and rapidly,but face challenges in balancing dynamic range and fidelity.Here,we have pioneered the demonstration of 10 true photon-number resolution using a superconducting microstrip detector,with readout fidelity reaching an impressive 98%and 90%for 4-photon and 6-photon events,respectively.Furthermore,our proposed dual-channel timing setup drastically reduces the amount of data acquisition by 3 orders of magnitude,allowing for real-time photon-number readout.We then demonstrate the utility of our scheme by implementing a quantum random-number generator based on sampling the parity of a coherent state,which guarantees inherent unbiasedness,robustness against experimental imperfections and environmental noise,as well as invulnerability to eavesdropping.Our solution boasts high fidelity,a large dynamic range,and real-time characterization for photon-number resolution and simplicity with respect to device structure,fabrication,and readout,which may provide a promising avenue towards optical quantum information science.

Superconducting microstrip single-photon detector with system detection efficiency over 90%at 1550 nm

Generally,a superconducting nanowire single-photon detector(SNSPD)is composed of wires with a typical width of∼100 nm.Recent studies have found that superconducting strips with a micrometer-scale width can also detect single photons.Compared with the SNSPD covering the same area,the superconducting microstrip single-photon detector(SMSPD)has smaller kinetic inductance,higher working current,and lower requirements in fabrication accuracy,providing potential applications in the development of ultralarge active area detectors.However,the study of SMSPD is still in its infancy,and the realization of its high-performance and practical use remains an open question.This study demonstrates a NbN SMSPD with a nearly saturated system detection efficiency(SDE)of∼92.2%at a dark count rate of∼200 cps,a polarization sensitivity of∼1.03,and a minimum timing jitter of∼48 ps at the telecom wavelength of 1550 nm when coupled with a single-mode fiber and operated at 0.84 K.Furthermore,the detector’s SDE is over 70%when operated at a 2.1 K closed-cycle cryocooler.

Hydrothermal synthesis, structure and magnetic properties of Ru doped La0.5Sr0.5MnO3

Synthesis, structure and magnetic properties of Ru doped perovskite structured manganite La0.5Sr0.5MnO3 were investigated experimentally. A hydrothermal method was used for the preparation of the samples. A high-temperature annealing process was also employed to make a comparison. A slightly enhancement of the unit cell volume was observed with the increase of Ru concentration. Scanning electron microscopy shows that the materials are made up of cube-shaped particles with dimension of several micrometers. Importantly, it is found that both the Curie temperature TC and saturation moment can be reduced by Ru doping. The value of coercive field is not affected by the introduction of Ru.

Impurity scattering effect in Pd-doped superconductor SrPt3P

We present a systematic study of the impurity scattering effect induced by Pd dopants in the super- conductor SrPt3P. Using a solid-state reaction method, we fabricated the Pd-doped superconductor Sr（Pt1-xPdx）3P. We found that the residual resistivity P0 increases quickly with Pd doping, whereas the residual resistance ratio （RRR） displays a dramatic reduction. In addition, both the nonlinear field-dependent behavior of the Hall resistivity Pxy and the strong temperature dependence of the Hall coefficient RH at low temperature are suppressed by Pd doping. All the experimental results can be explained by an increase in scattering by impurities induced by doping. Our results suggest that the Pt position is very crucial to the carrier conduction in the present system.