Objectives To develop prediction models that better estimate the pretest probability of coronary artery disease in low prevalence populations.Design Retrospective pooled analysis of individual patient data.Setting 18 hospitals in Europe and the United States.Participants Patients with stable chest pain without evidence for previous coronary artery disease, if they were referred for computed tomography (CT) based coronary angiography or catheter based coronary angiography (indicated as low and high prevalence settings, respectively). Main outcome measuresObstructive coronary artery disease (≥50% diameter stenosis in at least one vessel found on catheter based coronary angiography). Multiple imputation accounted for missing predictors and outcomes, exploiting strong correlation between the two angiography procedures. Predictive models included a basic model (age, sex, symptoms, and setting), clinical model (basic model factors and diabetes, hypertension, dyslipidaemia, and smoking), and extended model (clinical model factors and use of the CT based coronary calcium score). We assessed discrimination (c statistic), calibration, and continuous net reclassification improvement by cross validation for the four largest low prevalence datasets separately and the smaller remaining low prevalence datasets combined. ResultsWe included 5677 patients (3283 men, 2394 women), of whom 1634 had obstructive coronary artery disease found on catheter based coronary angiography. All potential predictors were significantly associated with the presence of disease in univariable and multivariable analyses. The clinical model improved the prediction, compared with the basic model (cross validated c statistic improvement from 0.77 to 0.79, net reclassification improvement 35%); the coronary calcium score in the extended model was a major predictor (0.79 to 0.88, 102%). Calibration for low prevalence datasets was satisfactory.Conclusions Updated prediction models including age, sex, symptoms, and cardiovascular risk factors allow for accurate estimation of the pretest probability of coronary artery disease in low prevalence populations. Addition of coronary calcium scores to the prediction models improves the estimates. IntroductionIn the United States, about 10.2 million people have chest pain complaints each year, 1 and more than 1.1 million diagnostic procedures of catheter based coronary angiography are performed on inpatients each year. 2 In a recent report based on the national cardiovascular data registry of the American College of Cardiology, 3 only 41% of patients undergoing elective procedures of catheter based coronary angiographies are diagnosed with obstructive coronary artery disease. The report's authors concluded that better risk stratification was needed, underlined by decision analyses showing that the choice of further diagnostic investigation in patients with chest pain depends primarily on the pretest probability of coronary artery disease. [4][5][6] The American College of Cardiology/American Heart Associatio...

Reactive oxygen species (ROS), important mediators of cell and tissue injury during inflammation, are produced by several types of inflammatory cells. The formation of ROS can be monitored by detection of lipid peroxidation products. The extremely broad spectrum of biological effects of aldehydic lipid peroxidation products has necessitated the development of a technique that enables the sensitive routine quantitation of aldehydes formed in biological materials. MalondiaJdehyde (MDA) is a by-product of enzymatic eicosanoid formation and an endproduct of nonenzymatic peroxidation of polyunsaturated fatty acids with three or more bisallylic double bonds, The determination of the thiobarbituric acid derivative of MDA (TBA-MDA) is a widely used method for estimating overall lipid peroxidation. We describe a rapid, isocratic, simple, and sensitive high-performance liquid chromatographic (HPLC) method with spectrafluorimetric detection for measurement oF MDA-TBA in human biological samples such as plasma, urine, wound secretions, amniotic fluid, sputum and tissue samples. By use of this method, picomole quantities of MDA can be readily and specifically detected in different biological materials. Coefficients of variation of repeated MDA-TBA assays were 4.4% within run and 6.9% from run to run. Reference values are given for a variety of human body fluids and for rat tissues.

A key to ultralong electron spin memory in quantum dots (QDs) at zero magnetic field is the polarization of the nuclei, such that the electron spin is stabilized along the average nuclear magnetic field. We demonstrate that spin-polarized electrons in n-doped (In,Ga)As/GaAs QDs align the nuclear field via the hyperfine interaction. A feedback onto the electrons occurs, leading to stabilization of their polarization due to formation of a nuclear spin polaron [I. A. Merkulov, Phys. Solid State 40, 930 (1998)]. Spin depolarization of both systems is consequently greatly reduced, and spin memory of the coupled electron-nuclear spin system is retained over 0.3 sec at temperature of 2 K.

This study confirms and expands data on the expression of AKR1B10 in HCC, suggesting that this enzyme is a valuable novel biomarker candidate for staging of HCC, especially in patients with underlying virus hepatitis or cirrhosis, and may present a new therapeutic target for multimodal therapy concepts. We confirm its prognostic value and conclude that high expression of AKR1B10 reflects a less aggressive tumour behaviour.

Purpose To evaluate the diagnostic accuracy of multiparametric ultrasonography (US) consisting of gray-scale US, color Doppler US, strain elastography, and contrast agent-enhanced US in the assessment of intratesticular lesions. Materials and Methods Institutional review board approval was obtained for this retrospective study. From January 2012 to December 2015, 55 focal testicular lesions that were indeterminate on gray-scale US scans were further characterized with color Doppler US, strain elastography, and contrast-enhanced US. Strain elastography was performed to assess tissue elasticity, and hard lesions were defined as malignant. Color Doppler US and contrast-enhanced US were performed to determine the absence or presence of vascularization. Avascular lesions were defined as benign. Histopathologic results or follow-up examinations served as reference standards. Correct classification rate, sensitivity, specificity, and likelihood ratio were calculated. Results Of 55 testicular lesions, 43 (78.2%) were benign and 12 (21.8%) were malignant. Single-modality sensitivities and specificities were 66.7% and 88.4% for color Doppler US, 100% and 76.7% for contrast-enhanced US, and 100% and 72.1% for strain elastography, respectively. Among 12 malignant lesions, color Doppler US failed to demonstrate vascularization in four (33.3%) lesions, which were positive for cancer at contrast-enhanced US. By combining strain elastography and contrast-enhanced US, a sensitivity of 100% and specificity of 93.0% were achieved in differentiating benign and malignant focal testicular lesions. Positive likelihood ratio was 5.7 for color Doppler US, 4.3 for contrast-enhanced US, 3.6 for strain elastography, 14.3 for strain elastography combined with color Doppler US, and 14.3 for strain elastography combined with contrast-enhanced US. Conclusion Multiparametric US allows for a reliable differentiation of benign and malignant intratesticular lesions and can potentially be useful in deciding whether orchiectomy can be replaced with follow-up or less invasive organ-sparing strategies. RSNA, 2017.

• Two proposed parameters were calculated (∆-CSA, R-CSA) and compared to NCS. • A defined sonoanatomical proximal landmark was used for the calculation. • Both parameters showed ability to detect CTS severity comparable to NCS. • Cut-off values could be determined for both parameters.

This report summarizes the outcome of 56 patients with cerebellar lesions of vascular origin, 40 patients with cerebellar infarction, and 16 with spontaneous cerebellar haemorrhage. All patients had computerized tomography: occlusive hydrocephalus was diagnosed in 75% of patients with cerebellar haemorrhage and in 23% with cerebellar infarction. Nine out of 10 patients survived after early surgical evacuation of the haematoma and 4 of them recovered completely. Two patients underwent only external ventricular drainage (EVD), one died after 2 days, and the other recovered with a moderate deficit. Three of 4 medically treated patients died within one week; all had developed occlusive hydrocephalus. The fourth medically treated patient recovered completely; consciousness had never deteriorated nor had occlusive hydrocephalus developed. Among 40 patients with cerebellar infarction, 13 developed progressive deterioration of consciousness; 7 of them underwent decompressive craniectomy of the posterior fossa and survived. One patient had only external ventricular drainage and died. Four out of the 5 medically treated patients died during the acute phase. From these observations and several reports in the literature, it is concluded that both cerebellar haemorrhage and infarction should be operated on as soon as progressive deterioration of consciousness develops. This occurs more frequently in patients with cerebellar haemorrhage than with cerebellar infarction. Individual decision-making in each case necessitates intensive neurosurgical observation.

We compare the asymmetry-induced exchange splitting δ1 of the bright-exciton ground-state doublet in self-assembled (In,Ga)As/GaAs quantum dots, determined by Faraday rotation, with its homogeneous linewidth γ, obtained from the radiative decay in time-resolved photoluminescence. Post-growth thermal annealing of the dot structures leads to a considerable increase of the homogeneous linewidth, while a strong reduction of the exchange splitting is simultaneously observed. The annealing can be tailored such that δ1 and γ become comparable, whereupon the carriers are still well confined. This opens the possibility to observe polarization entangled photon pairs through the biexciton decay cascade.PACS numbers: 71.36.+c, 73.20.Dx, 78.47.+p, Entangled photon pairs are a key requirement for the implementation of quantum teleportation schemes.[1] Typically, such photon pairs are created by parametric down conversion of a strongly attenuated laser beam in a non-linear optical crystal, with limited efficiency. Recently, the decay of a biexciton complex confined in a quantum dot (QD) has been suggested as an efficient source for polarization entangled photon pairs.[2] This concept was based on the assumption of an idealistic QD structure for which the valence band ground state has pure heavy hole character with angular momentum projections J h,z = ±3/2 along the heterostructure growth direction. When an electron-hole pair is injected, the momenta of the carriers become coupled by the exchange interaction. If the dot has perfect D 2d -symmetry, angular momentum is a good quantum number: the optically active states with momenta M = ±1 are degenerate, and their decay leads to emission of σ ± -circularly polarized photons.If the dot ground states are occupied by two electrons and two holes, each with opposite spin orientations, a spin singlet biexciton X 2 is formed, for whose decay two channels exist, as shown in Fig. 1 (upper panel left). The first photon is emitted with either σ + or σ − -polarization, and then the second photon with opposite polarization, as long as no spin flip occurs after the first process. Unless a polarization measurement is performed, the two photon polarization state is therefore described by2, forming an entangled state. A key requirement is that the photons emitted at each stage of the cascade are quasi-degenerate within their homogeneous linewidth, such that they cannot be distinguished by an energy measurement.Experiments have failed up to now to demonstrate such an entanglement, as only classical correlations were observed.[3] While some of the idealizations of the original proposal are well fulfilled, for example, for strongly confined self-assembled (In,Ga)As/GaAs quantum dots (such as the long exciton spin relaxation time as com- pared to the radiative lifetime [4], or the almost pure heavy-hole character of the valence band ground state [6]), a fundamental problem arises from the broken D 2d symmetry, which is reduced to at least C 2v or even lower symmetry in realistic dot structures. [7,8,...