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Quantum tomography of individual electrons, which in principle yields complete knowledge of their quantum states, is demonstrated by initially preparing them in a well-controlled quantum state called a leviton. Leviton-enabled electron quantum tomography Predicted in 1996 by Leonid Levitov and others, a new type of quasiparticle, called the leviton, was first created last year. The leviton consists of a single electron in a clean, well-controlled quantum state that can propagate through metal and could be of use as a robust carrier of quantum information in electronic circuits. Christian Glattli and colleagues now show it is possible to obtain complete knowledge of the wavefunction of an electron in the form of a leviton. Such quantum tomography measurements were previously impossible for electrons. The availability of this new tool should open up new avenues in the development of electron quantum optics. The complete knowledge of a quantum state allows the prediction of the probability of all possible measurement outcomes, a crucial step in quantum mechanics. It can be provided by tomographic methods.sup.1 which have been applied to atomic.sup.2,3, molecular.sup.4, spin.sup.5,6 and photonic states. For optical.sup.7,8,9 or microwave.sup.10,11,12,13 photons, standard tomography is obtained by mixing the unknown state with a large-amplitude coherent photon field. However, for fermions such as electrons in condensed matter, this approach is not applicable because fermionic fields are limited to small amplitudes (at most one particle per state), and so far no determination of an electron wavefunction has been made. Recent proposals involving quantum conductors suggest that the wavefunction can be obtained by measuring the time-dependent current of electronic wave interferometers.sup.14 or the current noise of electronic Hanbury-Brown/Twiss interferometers.sup.15,16,17. Here we show that such measurements are possible despite the extreme noise sensitivity required, and present the reconstructed wavefunction quasi-probability, or Wigner distribution function.sup.17, of single electrons injected into a ballistic conductor. Many identical electrons are prepared in well-controlled quantum states called levitons.sup.18 by repeatedly applying Lorentzian voltage pulses to a contact on the conductor.sup.19,20,21. After passing through an electron beam splitter, the levitons are mixed with a weak-amplitude fermionic field formed by a coherent superposition of electron-hole pairs generated by a small alternating current with a frequency that is a multiple of the voltage pulse frequency.sup.16. Antibunching of the electrons and holes with the levitons at the beam splitter changes the leviton partition statistics, and the noise variations provide the energy density matrix elements of the levitons. This demonstration of quantum tomography makes the developing field of electron quantum optics with ballistic conductors a new test-bed for quantum information with fermions.sup.20,22,23,24. These results may find direct application in probing the entanglement of electron flying quantum bits.sup.25, electron decoherence.sup.17 and electron interactions. They could also be applied to cold fermionic (or spin-1/2) atoms.sup.26., Author(s): T. Jullien [sup.1] , P. Roulleau [sup.1] , B. Roche [sup.1] , A. Cavanna [sup.2] , Y. Jin [sup.2] , D. C. Glattli [sup.1] Author Affiliations: (1) Service de [...]

The on-demand generation of pure quantum excitations is important for the operation of quantum systems, but it is particularly difficult for a system of fermions. This is because any perturbation [...]

Objectives: The study objective was to analyze the baseline characteristics of keratoconus (KC) patients at the Homburg Keratoconus Center from 2010 to 2021., Methods: This cross-sectional study included 3,674 eyes, with analysis of demographics, clinical findings, visual function, endothelial measurements, and topographic, tomographic, and corneal biomechanical data from the first visit., Results: Mean patient age was 36.3±13.8 years. The mean uncorrected distance visual acuity in log of minimal angle of resolution was 0.60 (20/80, Snellen equivalent), and the corrected mean was 0.3 (20/40). Of 1976 patients, 48.9% reported eye rubbing. Mean values (ranges) were 49.4±6.3 (36.3-78.0) D for steep keratometry, 462.4±66.0 (48.0-659.0) μm for thinnest corneal thickness, 9.7±8.7 (-0.5 to 88.8) for Belin/Ambrósio enhanced ectasia total deviation, 0.8±0.4 (0.0-1.0) for the Corvis biomechanical index, 0.9±0.2 (0.0-1.0) for the tomographic biomechanical index, 0.1±0.5 (-0.9 to 2.0) for the KC match index, 8.3±1.8 (2.2-17.7) mm Hg for corneal hysteresis, 7.1±2.2 (0.0-17.0) mm Hg for corneal resistance factor, and 2,562.9±326.3 (1,011-3,937) cells/mm2 for endothelial cell density. The average ABCDE KC stage was A2B3C1D1E2. Distance-corrected visual acuity correlated strongly with topometric, tomographic, and biomechanical data ( P <0.001)., Conclusions: This comprehensive description of baseline features of KC patients at a tertiary center provides a reference for further longitudinal and international multicentric studies., Competing Interests: The authors have no conflicts of interest to declare., (Copyright © 2023 Contact Lens Association of Ophthalmologists.)

Background: To investigate the risk factors for keratoconus progression in children (10 - 18 years old; age group 1) compared to young adults (19 - 35 years old; age group 2) and middle-aged adults (36 - 55 years old; age group 3)., Patients/methods: Ninety-seven children, 445 young adults, and 342 middle-aged adults underwent total ophthalmic examination including clinical refraction, slit lamp examination, corneal tomography, eye biometry, and biomechanical properties measurements. Comparisons were assessed among three age groups and between progressive and nonprogressive eyes. Logistic regression was applied to determine the potential prognostic factors for keratoconus progression in the three age groups., Results: Univariate logistic regression analysis show that the most prominent factors associated with progression were corneal posterior vertical radius (RVP), eye rubbing (RUB), slit lamp corneal thinning (SLT), contact lens use (CL), and central corneal thickness (CCT) in all age groups. Additionally, the anterior chamber volume (ACV) and keratoconus match index (KMI) were associated with progression in age group 1. Location of the thinnest corneal thickness at the vertical axis (TCTy), distance from apex to the thinnest point (BADISTAPEX), scissor reflection in retinoscopy (SKIAREFLEX), and Vogt striae were associated with progression in age group 2, and TCTy, anterior and posterior asphericity (ASPA and ASPP, respectively), BADISTAPEX, SKIAREFLEX, and Vogt striae were associated with progression in age group 3. The multivariate model with the highest predictability indicated RVP, ACV, and SLT as independent determinants of progression in age group 1 (AUC: 90%, sensitivity: 88.9%, specificity: 90.9%), RVP, ACV, SLT, and SKIAREFLEX in group 2 (AUC: 81.6%, sensitivity 88.5%, specificity: 70.3%), and RVP, SLT, Vogt striae, and CL in age group 3 (AUC: 80%, sensitivity 82.8%, specificity: 73%)., Conclusion: ACV and KMI seem to play a major role in the progression of pediatric KC compared to adults. This is probably due to different anatomical and biomechanical characteristics of a child's eye globe., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Background and Purpose: Nowadays, keratoconus (KC) is very well treatable in a stage-oriented manner. A wide range of designs and materials of contact lenses (CL) are available for the treatment of KC. The aim of this study was to evaluate the possibilities, the possible challenges and the visual outcome of lens fitting in KC eyes., Patients and Methods: This retrospective study includes data from 200 patients who received a lens fitting trial in our contact lens service between 2006 and 2016. We documented ophthalmological parameters, the type of prescribed CL, the number of required trial lenses and possible causes of the failure of the lens fitting., Results: The mean age at initial lens fitting was 33.9 ± 12.5 years. In 98.8% of the cases, the fitting was performed with rigid gas permeable lenses, in 90.1% with four-curve lenses. Of the total number of aspheric lenses prescribed, 87.5% were fitted in keratoconus stages "1" to "2" (topographic keratoconus classification; Oculus Keratograph). Back surface toric lenses or bitoric lenses were fitted to 61.7% in keratoconus stages "2 - 3" to "4". Before patients received their final CL, a median of 2 trial lenses were required (max. 16). Mean visual acuity with lens correction was 0.8 ± 0.2 at the initial fitting, mean visual acuity with glasses correction was 0.5 ± 0.3. In 7.7% of the eyes, the KC lens fitting was discontinued due to the advanced stage of keratoconus, requiring a corneal transplant. Reasons for discontinuing contact lens fitting included lens intolerance (2.3%), application problems (0.3%) or acute corneal hydrops (0.3%). Discontinuation of lens wearing due to incompatibilities or application problems occurred in only four cases (1.1%) in the further course after lens fitting., Conclusions: The use of contact lenses is an integral part of the stage-appropriate therapy of keratoconus. Good visual acuity can be achieved in all stages of keratoconus with a low drop-out rate. In most cases, the adjustment is carried out with rigid gas permeable lenses with a four-curve geometry. In initial stages, aspherical lenses may be sufficient. Toric lenses can be fitted in advanced stages when rotationally symmetrical lenses cannot achieve a satisfactory fit. If contact lenses have been successfully fitted, there are only a few cases in which patients abandon their contact lenses because of intolerance., Competing Interests: The authors declare that they have no conflict of interest. Parts of this work have been presented as free paper at the online congress of the German Ophthalmological Society (DOG) October 2020./Die Autorinnen/Autoren geben an, dass kein Interessenkonflikt besteht. Teile dieser Publikation wurden als freier Beitrag beim Online-Kongress der DOG im Oktober 2020 vorgestellt., (Thieme. All rights reserved.)

Background: This retrospective cross-sectional study aims to analyse the keratoconus (KC) stage distribution at different ages within the Homburg Keratoconus Center (HKC)., Methods: 1917 corneae (1000 patients) were allocated to decades of age, classified according to Belin's ABCD KC grading system and the stage distribution was analysed., Results: 73 per cent (n=728) of the patients were males, 27% (n=272) were females. The highest KC prevalence occurred between 21 and 30 years (n=585 corneae, 294 patients). Regarding anterior (A) and posterior (B) curvature, the frequency of A was significantly higher than B in all age groups for stage 0, 1 and 2 (A0>B0; A1>B1; A2>B2; p<0.03, Wilcoxon matched-pairs test). There was no significant difference between the number of A3 and B3, but significantly more corneae were classified as B4 than A4 in all age groups (p<0.02). The most frequent A|B combinations were A4|B4 (n=451), A0|B0 (n=311), A2|B4 (n=242), A2|B2 (n=189) and A1|B2 (n=154). Concerning thinnest pachymetry (C), most corneae in all age groups were classified as C0>C1>C2>C3>C4 (p<0.04, Wilcoxon matched-pairs test). For the best distance visual acuity (D), a significantly higher number of corneae were classified as D1 compared to D0 (p<0.008; D1>D0>D2>D3>D4)., Conclusion: The stage distributions in all age groups were similar. Early KC rather becomes manifest in the posterior than the anterior corneal curvature whereas advanced stages of posterior corneal curvature coincide with early and advanced stages of anterior corneal curvature. Thus, this study emphasises the necessity of posterior corneal surface assessment in KC as enabled by the ABCD grading system., Competing Interests: Competing interests: KX, SCG, SR, EZ, LH, TJ, UK, AL and BS declare that they do not have any financial disclosures in medicine. EF has received a travel grant to the Second and Third Ophthalmology Cystinosis Forum (Orphan Europe, Ulm, Germany) and an invitation to a seminar on presentation training organised by the Santen GmbH (Munich, Germany). TE was a member of the Institute of Experimental Ophthalmology, Saarland University Medical Center (Homburg, Germany), at the time of data collection and is now an employee of the Amiplant GmbH (Schnaittach, Germany)., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The optimal therapeutic strategy for patients with high-risk acute coronary syndrome without ST-segment elevation (NSTE-ACS) remains unclear., Objective: Our aim was to compare the effectiveness of an early invasive strategy and a delayed invasive strategy in the management of high-risk NSTE-ACS patients., Methods: This randomized clinical trial in a primarily pre-hospital setting enrolled patients with chest pain, electrocardiographic criteria for an NSTE-ACS, and at least one criterion of severity (ESC criterion or TIMI score >5). Patients were randomized to either an early invasive strategy (tirofiban infusion and coronary angiography within 6h) or delayed invasive strategy (as per guidelines and physician discretion; coronary angiography within 6h was not advised). The primary endpoint was the cumulative incidence of deaths, myocardial infarctions, or urgent revascularizations at 30days of follow-up. Secondary endpoints were failure of delayed management, length of hospital stay and long-term mortality., Results: Between January 2007 and February 2010, 170 patients were enrolled. The cumulative incidence of adverse outcomes was significantly lower for early invasive than delayed management (2% [95% CI 0-9] vs. 24% [95% CI 16-35], p<10(-4)). Delayed management failed in 24% of cases. The length of hospital stay was significantly shorter in patients undergoing angioplasty or treated with tirofiban within 6h (p=0.0003). Long-term mortality was 16% in both arms after a median follow-up of 4.1years., Conclusion: An early invasive strategy reduced major adverse cardiac events in patients with high-risk NSTE-ACS. Early angiography or tirofiban (GP IIb/IIIa inhibitor) infusion proved necessary in a quarter of patients assigned to delayed management., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

We show experimentally that, contrary to ordinary fluids, low Mach number granular pipe flows are linearly unstable toward the emission of acoustic waves. Exponential amplification of the waves propagating in the direction opposite to the flow is directly demonstrated. We relate the observed instability to the friction of the grains on the pipe, which pumps energy from the mean flow to coherent elastic waves. We show that the most amplified wavelength is proportional to the ratio of the tube radius to the friction coefficient.

Percutaneous transluminal coronary angioplasty (PTCA) is an alternative to fibrinolysis in the treatment of acute myocardial infarction (AMI). However, after balloon PTCA, the rate of early re-occlusion, of re-infarctus and of restenosis remains high. Stent implantation with antiplatelet drug regimen (aspirin, ticlid) limits these risks. Abciximab (new GPIIb/IIIa receptors inhibitor) reduces PTCA complications rate in the acute coronary syndromes. Intravenous administration of abciximab can restore a normal flow in the infarcted related coronary artery (IRA) after few minutes. A monocentric, non randomized, prospective pilot study was iniated to assess the feasibility of pre-hospital treatment with abciximab in preparation to primary PTCA stenting in AMI (primary endpoint) and to appreciate potential benefits in initial IRA patency as well as prevention of PTCA thrombotic complications (secondary endpoint). Between April 1997 and January 1998, 38 AMI were treated with abciximab in pre-hospital phase (group A). Mobil Intensive Care Unit (MICU) team implemented the treatment and guaranteed immediate transport to the cathlab (abciximab bolus-coronary angiography time = 37 +/- 17 min). Immediate results were compared to those of 198 paired patients who were treated for AMI during the same period (Group T). Initial IRA flow TIMI grade 3 was significantly higher in group A, 24%, than in group T, 9% (p < 0.017). The rates of per-procedural complications (no flow, distal embolism), of local complications, of transfusions were not significantly different. During 1 month follow-up, there was no significant difference between group A and group T concerning death, re-MI, stent thrombosis and new revascularization. To conclude, the pre-hospital treatment with abciximab in AMI is feasible by MICU medical team without any delay of the cathlab admission. It is associated with no increased hemorrhagic complications rate. The abciximab pre-hospital treatment improves the initial IRA patency. These encouraging preliminary results expect to be confirmed by larger, multicentric, randomized and prospective studies.

In 40 patients requiring mechanical ventilation for an episode of respiratory failure of various causes, prevalence of tricuspid regurgitation (TR) or other cause of vena caval backward flow (VCBF) was systematically investigated using transthoracic Doppler echocardiography. Quantification of TR was obtained from planimetry of the regurgitant jet during color Doppler examination. The influence of cyclic mechanical lung inflation was examined by contrast echography of the inferior vena cava and hepatic veins. All the 40 patients studied had TR, which was mild in 21, moderate in 9 and severe in 10. Using a planimetric scale, TR was more marked during mechanical ventilation, when compared with a brief period of spontaneous breathing. Moreover, contrast echocardiography demonstrated that systolic TR reached inferior vena cava and hepatic veins in 16 cases, and also evidenced direct mechanical action of lung inflation producing a pancardiac VCBF in 15 cases. This high incidence of TR and VCBF partially may explain the relatively poor reliability of the thermodilution method for measurement of cardiac output when used in ventilated patients.

1. Age-related changes in electrophysiological and pharmacological properties of rat ventricular cells have been investigated. 2. As compared to adults, transmembrane action potential (TAP) of aged rat myocardium exhibits a prolonged phase of repolarization. 3. For both young and aged groups tetrodotoxin reduces TAP duration. 4. Nifedipine and isoproterenol induce more pronounced modifications of the TAP in aged subjects. 5. Amiloride and tetraethylammonium ions prolong, for both groups, phase 2 of repolarization. This effect is more marked in the aged group. 6. Our results suggest that the prolonged TAP in aged myocardium could result from an age-related increase in calcium current.

Transmembrane action potential (AP), isotonic contraction and biochemical measurements were performed in 12-day, 1-, 3-, 14- and 24-month-old rat hearts. The major findings of this study are: (1) the AP and contraction duration decrease between 12 days and 1 month of age (growth period) and increase between 1 month and 24 months of age; (2) as compared with 1 month and 14 months, respectively, isotonic contraction peak shortening is lower at 12 days and 24 months of age; (3) the phosphorylation potential is higher during the postnatal period and decreases in an age-correlated manner; (4) the inorganic phosphate and glycogen contents are higher in the senescent heart. We conclude that, during the postnatal period the particular AP and the lower mechanical performances could be the result of immature sarcolemma and sarcoplasmic reticulum properties rather than modifications in the oxidative phosphorylation mechanism and by contrast, in senescent heart, that AP and contraction modifications could result from metabolic modifications.

We have investigated the effects of epidermal growth factor (EGF) on calcium ion channels in A431 epidermoid carcinoma cells. We have found that: -1- EGF stimulates Ca2+ channels. -2- EGF stimulated Ca2+ channels are voltage independent, exhibit a low conductance (8 pS) and a bursting multichannels activity (BMC). -3- Activation of the tyrosine-kinase function of the EGF receptor is required to generate Ca2+ current. -4- Inositol (1,4,5) triphosphate (Ins (1,4,5) P3) and EGF have similar effect on the channel activation. These results suggest that: stimulation of tyrosine-kinase activity of the EGF receptor, production of Ins (1,4,5)P3 and calcium entry via voltage independent channels are important connected steps in mediating the mitogenic effect of this growth factor.