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Quantum imaging is an ever expanding research field in which the aim is to exploit the quantum nature of light to enhance image reconstruction capabilities. Despite a number of successful demonstrations for quantum imaging, quantum microscopy still seems out of the range for practical applications due to different physical and technical reasons. Here, we propose an imaging method exploiting the quantum correlations of photon pairs and a scanning microscope to achieve fast, single mode quantum imaging. We first test our technique on a metal grating to estimate the resolution capabilities of our system. Moreover, we assess its potential in terms of the number of available independent pixels at full resolution compared to different quantum imaging approaches. Finally, we demonstrate scanning quantum microscopy of onion epithelial cells, paving the way toward scalable quantum microscopy for bio-physical applications. Our results, combined with the rapidly evolving photon-pair generation and detection technology toward the mid-infrared, could lead to an extension of quantum microscopy applications toward the mid-infrared to access the molecular fingerprint region. [ABSTRACT FROM AUTHOR]

We present an innovative approach for ultra-precise phase manipulation in integrated photonic quantum circuits. To this end, we employ generalized directional couplers that utilize a detuning of the propagation constant in optical waveguides by the overlap of adjacent waveguide modes. We demonstrate our findings in experiments with classical as well as quantum light. [ABSTRACT FROM AUTHOR]

An inadvertent indexing error has occurred in the derivation of the quantum Langevin equation presented in appendix A of our paper (2013 New J. Phys. 15 033008). In the previous version, the summation over the system modes â†q and the reservoir modes b†r was executed with independent indices. However, as each system mode is coupled to a different set of reservoir modes, the summation of the reservoir modes should rather depend on the system mode. Hence, we introduce a set of reservoir summation indices {rq}q=1,...,M, which are assigned to the individual system modes â†q . While this modification slightly alters equations (A.1)-(A.5) and (B.4)-(B.6), it has no implications to the results of the derivations, nor does it affect any result or conclusion in the main part of the paper. [ABSTRACT FROM AUTHOR]

The distribution of Ni in four lateritic Ni-goethites that were rapidly dehydroxylated to form hematite by shock heating at 340/400°C and 800°C for 30 min was investigated using synchrotron X-ray diffraction (SXRD), TEM spectroscopy (EELS and EFTEM) and synchrotron X-ray absorption spectroscopy (XAS). The Ni K-edge EXAFS results for non-heated samples showed three distinct Ni–Fe shells, including two edge-sharing (R Ni–Fe ∼ 3.01 and R Ni–Fe ∼ 3.22 Å) and a double corner-sharing (R Ni–Fe ∼ 3.52 Å) complex for most of the samples. These interatomic distances are indicative of Ni substituting for Fe in goethite, which has resulted in an expansion in the goethite structure along the a-axis direction and a contraction along the b-axis direction. Ravensthorpe Ni goethite was considerably different from the other goethites, with two Ni–O interatomic lengths (R Ni–O ∼ 2.04 and 2.46 Å), an edge-sharing (R Ni–Fe ∼3.04 Å) and a corner-sharing (R Ni–Fe ∼ 3.56 Å) complex. The R Ni–O ∼ 2.46 Å bond length is not indicative of Ni substituting for Fe in goethite, nor is it associated with single or multiple scattering events in NiO, Ni(OH)2 or Ni substituting for Fe in Fe oxides. The corresponding Ni K-edge EXAFS results for 340/400°C and 800°C heated samples (i.e. hematite) were very similar. Four distinct metal neighbours correspond to Fe/Ni in face-sharing (R Ni–Fe ∼ 2.87–2.91 Å) and three different corner-sharing complexes (R Ni–Fe ∼ 3.37– 3.41 Å, R Ni–Fe ∼ 3.62– 3.64 Å and R Ni–Fe ∼ 3.92– 4.09 Å) represent Ni substituting for Fe in hematite. The fourth shell is indicative of an inner sphere surface complex. EFTEM maps for Ni in goethite are consistent with the formation of a surface complex as they provide evidence for clustering of Ni on the surface of neoformed hematite crystals. There was no evidence from EXAFS or SXRD supporting the formation of discrete Ni phases (e.g. NiO) as a result of shock heating. Therefore, for Ni-goethites subjected to shock heating at 800°C (i.e. high-temperature dehydroxylation to hematite), most of the Ni is retained in the structures of the neoformed hematites, whereas some of the Ni migrates to the surface of the neoformed hematite where it forms a surface complex. During acid dissolution (e.g. heap leaching) of oxide-type lateritic Ni ores, Ni on the hematite surface is more accessible to acid solutions; therefore, these results may provide a basis for more efficient extraction methods for Ni in oxide-type lateritic Ni ores, as well as providing information on the possible redistribution of Ni in heated goethite-rich soils. [ABSTRACT FROM AUTHOR]

Abstract: Worldwide bauxite residue disposal areas contain an estimated 2.7billiontonnes of residue, increasing by approximately 120milliontonnesperannum. The question of what to do with bauxite residue arose with the development of the Bayer process for alumina refining and the recognition that it generated a large amount of waste material. In the subsequent 120years, residues have been primarily disposed into long-term storage, with a wide range of industry practice depending on local circumstances. Ideally this residue would be utilized as an industrial by-product for other applications, leading to a zero waste situation. Despite over 50years of research and hundreds of publications and patents on the subject, little evidence exists of any significant utilization of bauxite residue. In this review of public domain information the reasons are examined, future opportunities are identified, and a way forward is proposed. All avenues of residue “re-use” (or more appropriately “use”) are considered, but emphasis is on the few highest volume uses of lowest risk. Utilization is defined as taking the residue in some non-hazardous form (as a by-product) from the alumina refinery site and then using it as feedstock for another distinct application. Although residues from different bauxites have generic similarities, their specific make-up and residue location can influence their suitability for a given type of use. There are four primary reasons for inaction on residue use: volume, performance, cost and risk, with the last two probably being paramount. In terms of cost there are better options for raw material input from virgin sources (lower cost for better grades) that do not come with the same perceived risks as bauxite residue. The risks are composition based (technical and community perception) and relate to: soda, alkalinity, heavy metals and low levels of naturally occurring radioactive material (NORM). Amongst the outcomes of this review are priority research recommendations to address the knowledge gaps identified that, amongst other factors, are impeding the implementation of residue use. This is the second in a series of four related reviews examining bauxite residue issues in detail. [Copyright &y& Elsevier]

Abstract: Bauxite residue has been continuously produced since the inception of the alumina/aluminium industry in the late nineteenth century. The global inventory of bauxite residue reached an estimated 2.7billiontonnes in 2007 increasing at 120milliontonnes per annum. This growth highlights the urgency to develop and implement improved means of storage and remediation, and to pursue large-volume utilization options of residue as an industrial by-product. This review looks at current management practices for disposal and amendment, and how each unit process influences residue properties. Since 1980 the trend has been away from lagoon-type impoundments towards “dry” stacking; this reduces the potential for leakage, reduces the physical footprint and improves recoveries of soda and alumina. Associated technical developments in residue neutralization are considered with possible future practices in residue disposal and how that might best integrate with future utilization. For example, hyperbaric steam filtration is an emerging technology that could discharge residue as a dry, granular material of low soda content. Such properties are beneficial to long term storage and remediation, but importantly also to future utilization. Although residue has a number of characteristics of environmental concern, the most immediate and apparent barrier to remediation and utilization (improved sustainability) is its high alkalinity and sodicity. The sustained alkalinity is the result of complex solid-state and solution phase interactions while its sodicity arises from the use of caustic soda (NaOH) for digestion. This is the first in a series of four related reviews examining bauxite residue issues in detail. [Copyright &y& Elsevier]

Abstract: Worldwide bauxite residue disposal areas contain an estimated 2.7billion tonnes of bauxite residue, increasing by ~120million tpa. The future management of this residue is of increasing environmental concern. Ideally it would be utilized as an industrial by-product for other applications (the zero waste situation), but realistically the drivers for zero waste are not high and there are significant cost and liability barriers to implementation. Any future utilization will most likely be based on contemporary production and residue currently consigned to long-term storage is unlikely to be recovered, thus the environmental impact risk remains. This prompts the question as to whether remediation can be conducted in situ, i.e. changing the residue chemistry without specifically re-excavating for conventional processing. In this review the key parameters of residue chemistry and its physical properties are considered in the context of what is required for a remediated residue to support a viable eco-system, i.e. what is required for rehabilitation in terms of a series of easily understandable goals. Specifically residue characteristics of stable residue solution such that; pH of 5.5–9.0, sodium adsorption ratio (SAR) of ≤7, exchangeable sodium percentage (ESP) of ≤9.5, residual sodium carbonate (RSC) of ≤1.25, electrical conductivity (EC) of <4mS/cm. These goals are a long way from typical existing residue. Bauxite residue itself is the by-product of an iconic hydrometallurgical process, namely the Bayer process. While understanding the hydrometallurgical consequences is one key to the successful implementation of a remediation strategy, it is also clear that the key to in situ remediation is most likely not conventional hydrometallurgy but a systematic and targeted bioremediation approach. The most promising pathway for an in situ rehabilitated bauxite residue disposal area would appear to be bioremediation based on strategies developed for saline–sodic soils using halophyte plants and alkaliphilic microbes to effectively farm sodium from the system and mitigate pH, respectively. On bauxite residue surfaces the advantages and similarities should closely parallel saline–sodic agricultural soils. Halophytes provide great potential to accomplish some of the necessary rehabilitation goals indicated. Practical environmental rehabilitation attempts to date have been more concerned with BRDA closure in a cosmetic sense. These have had some limited success and probably reflect the aim of the work to achieve re-vegetation, relying on a limited understanding of the residue chemistry and lacking detailed information on individual plant responses and tolerances. It is proposed that research design for bioremediation should commence with a more rigorous plant, fungi and microbe selection in conjunction with a better understanding of residue chemistry. That is, tackling both the abiotic and biotic aspects of the problem systematically, especially as the sodium halophyte farming would initially be progressing into an even more extreme environment. This cannot be an unassisted process; without intervention BRDA environments would remain sterile for an extended period of time. Amendments such as applied gypsum can further displace Na+ from the residue exchange complexes and in conjunction with other divalent cation strategies control pH within halophyte tolerance. Both halophyte produced organic acids and halophyte promoted microbial populations provide H+ and increase the partial pressure of CO2 in the rooting zones to further the rehabilitation process. Suitable drainage strategies, along with other additions (organic waste, sewage sludge, macro and micro-nutrients) will promote plant and microbe survival. Whilst this approach would not be envisaged to be either capital or operating intensive, it is not a “quick-fix”. Bio-remediation is a process that would require multiple growing seasons, but well within the typical lifetime of a refinery operation. This is the final in a series of four related reviews examining bauxite residue issues in detail. [Copyright &y& Elsevier]

Abstract: A detailed understanding of the complex buffering and neutralization chemistry of bauxite residue remains the key to improved management, both in terms of reduced environmental impact for current storage practices, legacy costs and for the utilization of the material as an industrial by-product for other applications. In spite of 120years of continuous industrial production, the nature of residue and the chemistry of remediation is still poorly understood. This review brings together what is known of residue behavior and outlines the existing knowledge gaps in our understanding. It examines those aspects of the Bayer process that relate to the creation of the alkalinity in residue and discusses in detail the complex chemical reactions that govern the neutralization behavior. pH is the “master variable” in the chemistry of residue and is strongly buffered by the presence of multiple alkaline solids. The pH in untreated residue liquor (washer overflow) ranges over 9.2–12.8 with an average value of 11.3±1.0. This high alkalinity is the primary reason for residue classification as a hazardous material, and in conjunction with the sodic content the primary reason that residue will not support plant life. The pH is highly buffered by the presence of alkaline solids (various hydroxides, carbonates, aluminates and aluminosilicates) that are formed by the action of caustic soda on bauxite in the Bayer process refinery. The presence of such Bayer process characteristic solids causes the acid neutralization behavior of residues to be highly complex and makes impractical the removal of alkalinity by simply washing with water. This chemistry also impacts physical properties e.g. bulk density, sedimentation rates and compaction, hydraulic conductivity, drying rates and dusting behavior, and physical strength after drying. Understanding how surface charge develops, distributes and abates in the residue mineral assemblage as a function of acid input will be paramount to understanding neutralization reactions overall, to successfully model them and eventually to implement the most effective neutralization measures that create conditions at the surface conducive to reduced environmental impact, e.g. to enable plant growth. Once this is understood a model can be constructed for the neutralization behavior of bauxite residue based on the underlying mineralogy and its relationship to overall surface charge. This is the third in a series of four reviews examining bauxite residue issues in detail. [Copyright &y& Elsevier]

• The nickel (Ni) hyperaccumulator Alyssum murale has been developed as a commercial crop for phytoremediation/phytomining Ni from metal-enriched soils. Here, metal co-tolerance, accumulation and localization were investigated for A. murale exposed to metal co-contaminants. • A. murale was irrigated with Ni-enriched nutrient solutions containing basal or elevated concentrations of cobalt (Co) or zinc (Zn). Metal localization and elemental associations were investigated in situ with synchrotron X-ray microfluorescence (SXRF) and computed-microtomography (CMT). • A. murale hyperaccumulated Ni and Co (> 1000 µg g−1 dry weight) from mixed-metal systems. Zinc was not hyperaccumulated. Elevated Co or Zn concentrations did not alter Ni accumulation or localization. SXRF images showed uniform Ni distribution in leaves and preferential localization of Co near leaf tips/margins. CMT images revealed that leaf epidermal tissue was enriched with Ni but devoid of Co, that Co was localized in the apoplasm of leaf ground tissue and that Co was sequestered on leaf surfaces near the tips/margins. • Cobalt-rich mineral precipitate(s) form on leaves of Co-treated A. murale. Specialized biochemical processes linked with Ni (hyper)tolerance in A. murale do not confer (hyper)tolerance to Co. A. murale relies on a different metal storage mechanism for Co (exocellular sequestration) than for Ni (vacuolar sequestration). [ABSTRACT FROM AUTHOR]

Aims: The scope of this study was to assess the potential value of pulmonary venous flow diastolic deceleration time to predict end-diastolic pressure and stratify patients with regard to elevation of left ventricular end-diastolic pressures.Methods and Results: In 174 consecutive patients, pulmonary venous flow diastolic deceleration time was determined and compared with left ventricular end-diastolic pressures measured invasively. The sample was randomly divided into two subgroups of equal size for modelling of prediction and independent testing of the model. Predicted left ventricular end-diastolic pressures calculated from pulmonary venous flow diastolic deceleration time (left ventricular end-diastolic pressures = −10.87 + 5261/pulmonary venous flow diastolic deceleration time) agreed well with measured left ventricular end-diastolic pressures (mean difference: -1.3 ± 3.4 mmHg). The correlation of left ventricular end-diastolic pressures with pulmonary venous flow diastolic deceleration time is fair (r=0.73989). A value of pulmonary venous flow diastolic deceleration time <220 ms is suggestive of elevated left ventricular end-diastolic pressures and should be monitored. A value of pulmonary venous flow diastolic deceleration time <190 ms predicts elevated left ventricular end-diastolic pressures. A value of pulmonary venous flow diastolic deceleration time <165 ms predicts severely elevated left ventricular end-diastolic pressures. With 190 ms as a cut-off value for elevated and 165 ms for severely elevated left ventricular end-diastolic pressures, cross-table analysis classifies all patients with normal left ventricular end-diastolic pressures correctly. No patient with severe elevation (<18 mmHg) of left ventricular end-diastolic pressures is classified as normal (χ2=102, P<0.0001).Conclusion: Pulmonary venous flow diastolic deceleration time is an appropriate non-invasive measurement to stratify patients with respect to elevation of left ventricular end-diastolic pressures. [ABSTRACT FROM AUTHOR]

The present study was undertaken to determine the influence of hyperphagia on the adaptive changes occurring in the rat jejunal mucosa as a result of intestinal resection. One group of resected rats was subjected to pair feeding with a sham-operated population, whilst another group was nourished ad libitum. The animals which ate ad libitum developed hypertrophy of the mucosa which was accompanied by increased glucose absorption in vivo without changes in enzyme levels. These alterations were much less pronounced in the pair-fed group of resected animals, a finding that indicates that the adaptive changes are at least partially influenced by increased luminal nutrition. [ABSTRACT FROM PUBLISHER]

Activation of vascular β-adrenergic receptors prevents an increase in vascular permeability caused by free radicals or inflammatory peptides. Methylxanthines seem to have similar protective effects on vascular endothelium. In the present study we investigated the effect of theophylline on the β-adrenergic receptor expression and cAMP concentrations in cultured endothelial and smooth muscle cells from bovine aorta. Comparable values for β-receptor density and binding affinity were detected in both cell types. Isoproterenol induced significant downregulation of β-receptors in endothelial (BAEC: −60.5%) and smooth muscle cells (BASMC: −52.5%; P < 0.01). Incubation of endothelial cells with theophylline (4 µg/ml and 40 µg/ml) for 24 hours did not affect β-receptor expression, whereas in smooth muscle cells the β-receptor density was reduced for −31.5% and −28.7, respectively. In endothelial cells a transient effect on cAMP concentrations was observed after stimulation with isoproterenol (1 µM), but no effect was found in theophylline treated endothelial cells. Stimulation of intact smooth muscle cells with isoproterenol and theophylline (4 µg/ml and 40 µg/ml) resulted in a significant increase of cAMP concentrations after 60 and 240 minutes. The present data suggest a novel, celltype specific effect of theophylline on the β-adrenergic receptor expression in vascular smooth muscle cells in vitro. [ABSTRACT FROM AUTHOR]

ACE inhibitors are superior to other vasodilators in the treatment of congestive heart failure and may be advantageous in patients with myocardial infarction and hypertension. The mechanisms mediating these beneficial effects are not clear. The present article discusses the mechanisms leading to augmented release of endothelium-derived nitric oxide during ACE inhibition.Acute potentiation of bradykinin (Bk)-induced vasodilation was studied in rings of bovine and human coronary arteries mounted in organ chambers for recording of isometric force. The ACE inhibitors captopril, enalaprilat, fosinoprilat, lisinopril, or ramiprilat alone did not affect vascular tone in isolated coronary artery preparations with intact endothelium. However, in the presence of exogenous Bk, kallidin, or one of the slowly degradable Bk2-receptor agonists D-Arg(Hyp3)-Bk or [Hyp3-Tyr(Me)8].Bk they elicited potent concentration-dependent relaxations. Relaxations in response to lisinopril were not observed in the presence of other vasodilators. They were prevented by mechanical removal of the endothelium, inhibition of nitric oxide synthase or Bk2-receptor blockade. The data indicate that ACE inhibitors potentiate the effects of Bk on endothelial cells by a local mechanism, probably independent of the degradation of bradykinin.The chronic effects of ACE inhibitors on endothelial function were compared with those of selective angiotensin(AT)1, receptor blockade in cyclosporin A (CsA) treated rats. Chronic AT blockade alone does not affect endothelium-dependent relaxations and increases contractions to ATII in the rat aorta. Combination of CsA with either an ACE-inhibitor or an AT2 receptor antagonist prevented the endothelial dysfunction in the rat arta observed after CsA alone. The data suggest a role for ATII in the development of chronic endothelial dysfunction. [ABSTRACT FROM PUBLISHER]

Abstract: We present a compact interferometric autocorrelator that allows the characterization of ultrashort laser pulses in the visible light domain (370–740nm). The presented device uses a GaN photodiode with corresponding two-photon absorption. Different GaN and AlGaN photodiodes were characterized for this purpose. Despite AlGaN diodes have a better matched bandgap for this application, we have found that only the GaN diodes show sufficient nonlinear behavior. Using the autocorrelator we were able to characterize ultrashort frequency doubled Ti:Sapphire laser pulses with a pulse duration down to 18fs in the second harmonic having just a few hundred nanojoules of pulse energy. The broadband behavior and extension towards the UV along with the need for only low energetic pulses are the novelties of this device. [Copyright &y& Elsevier]

Introduction: Tenofovir is integral to antiretroviral therapy (ART) and pre‑exposure prophylaxis (PrEP) for HIV; however, neuropsychiatric adverse events (NPAEs) associated with its use have not been systematically investigated., Objectives: This systematic review aimed to characterize common NPAEs occurring during tenofovir‑based ART and PrEP, and to assess the specific role of tenofovir in their emergence., Patients and Methods: Four literature databases and 3 trial registries were searched up to December 31, 2023 for randomized controlled trials reporting NPAEs in treatment‑naive adults receiving tenofovir‑based ART or PrEP. Meta‑analyses were conducted to compare tenofovir (with / without emtricitabine) with placebo and tenofovir alafenamide-based with tenofovir disoproxil fumarate-based regimens., Results: A total of 69 trials (62 on ART, 7 on PrEP) including 29 340 patients on tenofovir‑based therapies identified headache, dizziness, insomnia, and depression as common NPAEs, especially in HIV studies. Meta‑analyses of tenofovir (with / without emtricitabine) vs placebo only indicated an increased risk of dizziness (odds ratio [OR], 1.32; 95% CI, 1.09-1.59; P = 0.004). Comparisons between tenofovir alafenamide and disoproxil fumarate did not show significant differences in NPAE risks, although sensitivity analyses suggested a higher risk of headache with tenofovir alafenamide in HIV studies (OR, 1.24; 95% CI, 1.01-1.52; P = 0.04)., Conclusions: Common occurrence of NPAEs in tenofovir‑based HIV multidrug regimens highlights the need to screen HIV patients for neuropsychiatric complications. The lack of effect of tenofovir, as compared with placebo, for most analyzable NPAEs suggests its favorable safety profile. However, a possible increase in the dizziness risk on tenofovir, and a potentially elevated risk of headache on tenofovir alafenamide- as compared with tenofovir disoproxil fumarate-based regimens in HIV therapy merit further investigation.

We present an experimental implementation of a polarization-entangled photon-pair source based on beam displacers. The down-converted photons are emitted via spontaneous parametric downconversion in a non-degenerate and type-0 process. We obtain a state fidelity of F = 0.975 ± 0.004 and violate a Clauser-Horne-Shimony-Holt (CHSH) inequality with $\mathcal {S}=2.75\pm 0.01$. Our source also uses thin crystals for applications in quantum imaging, taking advantage of the large number of spatial modes. We estimate that our source could produce 550 ± 12 spatial modes.

Imaging based on the induced coherence effect makes use of photon pairs to obtain information of an object without detecting the light that probes it. While one photon illuminates the object, only its partner is detected, so no measurement of coincidence events is needed. The sought-after object's information is revealed, observing a certain interference pattern on the detected photon. Here, we demonstrate experimentally that this imaging technique can be made resilient to noise. We introduce an imaging distillation approach based on the interferometric modulation of the signal of interest. We show that our scheme can generate a high-quality image of an object even against noise levels up to 250 times the actual signal of interest. We also include a detailed theoretical explanation of our findings.

The distribution of entanglement via satellite links will drastically extend the reach of quantum networks. Highly efficient entangled photon sources are an essential requirement towards overcoming high channel loss and achieving practical transmission rates in long-distance satellite downlinks. Here we report on an ultrabright entangled photon source that is optimized for long-distance free-space transmission. It operates in a wavelength range that is efficiently detected with space-ready single photon avalanche diodes (Si-SPADs), and readily provides pair emission rates that exceed the detector bandwidth (i.e., the temporal resolution). To overcome this limitation, we demultiplex the photon flux into wavelength channels that can be handled by current single photon detector technology. This is achieved efficiently by using the spectral correlations due to hyper-entanglement in polarization and frequency as an auxiliary resource. Combined with recent demonstrations of space-proof source prototypes, these results pave the way to a broadband long-distance entanglement distribution network based on satellites.

Quantum resources can provide supersensitive performance in optical imaging. Detecting entangled photon pairs from spontaneous parametric down conversion (SPDC) with single-photon avalanche diode (SPAD) image sensor arrays (ISAs) enables practical wide-field quantum-enhanced imaging. However, matching the SPDC wavelength to the peak detection efficiency range of complementary metal-oxide-semiconductor (CMOS) compatible mass-producible SPAD-ISAs has remained technologically elusive, resulting in low imaging speeds to date. Here, we show that a recently developed visible-wavelength entangled photon source enables high-speed quantum imaging. By operating at high detection efficiency of a SPAD-ISA, we increase acquisition speed by more than an order of magnitude compared to previous similar quantum imaging demonstrations. Besides being fast, the quantum-enhanced phase imager operating at short wavelengths retrieves nanometer scale height differences, tested by imaging evaporated silica and protein microarray spots on glass samples, with sensitivity improved by a factor of 1.351 ± 0.004 over equivalent ideal classical imaging. This work represents an important stepping stone towards scalable real-world quantum imaging advantage, and may find use in biomedical and industrial applications as well as fundamental research.

Background: Misuse of prescription stimulants (PS) has been reported among students to enhance academic performance in Flanders (Belgium). However, PS misuse among students in the French-speaking community is unknown. The main purpose of the study was to estimate the prevalence of medical use and misuse of PS by university students in the French-speaking community (Belgium), and to investigate the reasons and sources associated with PS misuse., Methods: A cross-sectional online survey was performed in 2018. All university students 18 years and older were invited to participate and asked about PS use, including medical (i.e., used for therapeutic purposes) and nonmedical reasons and sources of PS., Results: In total, 12 144 students participated in the survey (median age = 21 years, 65.5% female). The estimated prevalence of PS use was 6.9% (ever use) and 5.5% (past-year). Among ever users, 34.7% were classified as medical users and 65.3% as misusers. Lifetime prevalence of misuse was estimated at 4.5%. The most common reason for medical use was treatment of attention disorder (85.9%). Reasons for misuse were mainly to improve concentration (76.1%) or to stay awake and study longer (50.7%). Friends or acquaintances inside the student community and general practitioners were the main sources of PS for misuse (41.5% and 23.5%, respectively)., Conclusions: This study found that rates of misuse of PS in French-speaking universities in Belgium were in line with studies conducted in Flanders and Europe. Academic institutions can use these results to tailor their drug prevention campaigns., (© 2022. The Author(s).)

Holography exploits the interference of a light field reflected/transmitted from an object with a reference beam to obtain a reconstruction of the spatial shape of the object. Classical holography techniques have been very successful in diverse areas such as microscopy, manufacturing technology, and basic science. However, detection constraints for wavelengths outside the visible range restrict the applications for imaging and sensing in general. For overcoming these detection limitations, we implement phase-shifting holography with nonclassical states of light, where we exploit quantum interference between two-photon probability amplitudes in a nonlinear interferometer. We demonstrate that it allows retrieving the spatial shape (amplitude and phase) of the photons transmitted/reflected from the object and thus obtaining an image of the object despite those photons are never detected. Moreover, there is no need to use a well-characterized reference beam, since the two-photon scheme already makes use of one of the photons as reference for holography.

Background Phenylketonuria is the most common inborn error of amino acid metabolism, where oxidative stress and collateral metabolic abnormalities are likely to cause cardiac structural and functional modifications. We aim herein to characterize the cardiac phenotype of adult subjects with phenylketonuria using advanced cardiac imaging. Methods and Results Thirty-nine adult patients with phenylketonuria (age, 30.5±8.7 years; 10-year mean phenylalanine concentration, 924±330 µmol/L) and 39 age- and sex-matched healthy controls were investigated. Participants underwent a comprehensive cardiac magnetic resonance and echocardiography examination. Ten-year mean plasma levels of phenylalanine and tyrosine were used to quantify disease activity and adherence to treatment. Patients with phenylketonuria had thinner left ventricular walls (septal end-diastolic thickness, 7.0±17 versus 8.8±1.7 mm [ P <0.001]; lateral thickness, 6.1±1.4 versus 6.8±1.2 mm [ P =0.004]), more dilated left ventricular cavity (end-diastolic volume, 87±14 versus 80±14 mL/m 2 [ P =0.0178]; end-systolic volume, 36±9 versus 29±8 mL/m 2 [ P <0.001]), lower ejection fraction (59±6% versus 64±6% [ P <0.001]), reduced systolic deformation (global circumferential strain, -29.9±4.2 % versus -32.2±5.0 % [ P =0.027]), and lower left ventricular mass (38.2±7.9 versus 47.8±11.0 g/m 2 [ P <0.001]). T1 native values were decreased (936±53 versus 996±26 ms [ P <0.001]), with particular low values in patients with phenylalanine >1200 µmol/L (909±48 ms). Both mean phenylalanine ( P =0.013) and tyrosine ( P =0.035) levels were independently correlated with T1; and in a multiple regression model, higher phenylalanine levels and higher left ventricular mass associate with lower T1. Conclusions Cardiac phenotype of adult patients with phenylketonuria reveals some traits of an early-stage cardiomyopathy. Regular cardiology follow-up, tighter therapeutic control, and prophylaxis of cardiovascular risk factors, in particular dyslipidemia, are recommended.

Purpose: This prospective case series is aimed at exploring optical coherence tomographic angiography (OCT-A) as a treatment monitoring tool in patients treated for retinal angiomatous proliferation (RAP)., Methods: Twelve treatment-naïve RAP patients were included, with a median age of 79 years (range 65-90). Patients were imaged with an experimental 1,040-nm swept-source phase-resolved OCT-A instrument before and after treatment. Treatment consisted of either intravitreal bevacizumab or triamcinolone injections with or without photodynamic therapy (PDT). Abnormal blood flow after treatment was graded as increased, unchanged, decreased, or resolved., Results: OCT-A images before and after treatment could be obtained in 9 patients. The median follow-up period was 10 weeks (range 5-19). After various treatments, the RAP lesion resolved in 7 patients, in 1 patient the OCT-A depicted decreased flow in the lesion, and 1 patient showed unchanged abnormal blood flow. Monotherapy with intravitreal bevacizumab injections resolved RAP in 1 out of 2 patients. Combined therapy of bevacizumab with PDT resolved RAP in 6 out of 7 patients., Conclusions: OCT-A visualized resolution of abnormal blood flow in 7 out of 9 RAP patients after various short-term treatment sequences. OCT-A may become an important noninvasive monitoring tool for optimizing treatment strategies in RAP patients., (© 2018 The Author(s) Published by S. Karger AG, Basel.)

The vast development of integrated quantum photonic technology enables the implementation of compact and stable interferometric networks. In particular, laser-written waveguide structures allow for complex 3D circuits and polarization-encoded qubit manipulation. However, the main limitation in the scaling up of integrated quantum devices is the single-photon loss due to mode-profile mismatch when coupling to standard fibers or other optical platforms. Here we demonstrate tapered waveguide structures realized by an adapted femtosecond laser writing technique. We show that coupling to standard single-mode fibers can be enhanced up to 77% while keeping the fabrication effort negligible. This improvement provides an important step for processing multiphoton states on chip.

Since the advent of large-scale U mining, processing, and enrichment for energy or weapons production, efficient capture and disposal of U, transuranics, and daughter radionuclides has constituted an omnipresent challenge. In this study, we investigated uranyl (UO 2 2+ ) sequestration by hydrotalcite (HTC) as a coprecipitation or surface adsorption reaction scenario. The master variables of the study were pH (7.0 and 9.5) and CO 2 content during the reactions (CO 2 -rich, CO 2 r vs CO 2 -depleted, CO 2 p). In addition, we compared the outcomes of U-HTC coprecipitation reactions between pristine salt precursors and barren U mine wastewater (lixiviant). Extended X-ray absorption fine structure spectra revealed that uranyl adsorbs on the HTC surface as inner-sphere complexes in CO 2 r and CO 2 p systems with U-Mg/Al interatomic distances of ∼3.20 and ∼3.35 Å indicative of single-edge ( 1 E) and double-edge ( 2 E) sharing complexes, respectively. Partial coordination of uranyl by carbonate ligands in CO 2 r systems does not appear to hinder surface complexation, suggesting ligand-exchange mechanisms to be operative for the formation of inner-sphere surface complexes. Uranyl symmetry is maintained when coprecipitated with Al and Mg from synthetic or barren lixiviant solutions, precluding incorporation into the HTC lattice. Uranyl ions, however, are surrounded by up to 3-5 Mg/Al atoms in coprecipitated samples interfering with HTC crystal growth. Future research should explore the potential of Fe(II) or Mn(II) to reduce U(VI) to U(V), which is conducive for U incorporation into octahedral crystal lattice positions of the hydroxide sheet., Competing Interests: The authors declare no competing financial interest.

We propose the realization of photonic circuits whose dynamics is governed by advanced-retarded differential equations. Beyond their mathematical interest, these photonic configurations enable the implementation of quantum feedback and feedforward without requiring any intermediate measurement. We show how this protocol can be applied to implement interesting delay effects in the quantum regime, as well as in the classical limit. Our results elucidate the potential of the protocol as a promising route towards integrated quantum control systems on a chip.

Transport phenomena on a quantum scale appear in a variety of systems, ranging from photosynthetic complexes to engineered quantum devices. It has been predicted that the efficiency of coherent transport can be enhanced through dynamic interaction between the system and a noisy environment. We report an experimental simulation of environment-assisted coherent transport, using an engineered network of laser-written waveguides, with relative energies and inter-waveguide couplings tailored to yield the desired Hamiltonian. Controllable-strength decoherence is simulated by broadening the bandwidth of the input illumination, yielding a significant increase in transport efficiency relative to the narrowband case. We show integrated optics to be suitable for simulating specific target Hamiltonians as well as open quantum systems with controllable loss and decoherence.

Fourier transforms, integer and fractional, are ubiquitous mathematical tools in basic and applied science. Certainly, since the ordinary Fourier transform is merely a particular case of a continuous set of fractional Fourier domains, every property and application of the ordinary Fourier transform becomes a special case of the fractional Fourier transform. Despite the great practical importance of the discrete Fourier transform, implementation of fractional orders of the corresponding discrete operation has been elusive. Here we report classical and quantum optical realizations of the discrete fractional Fourier transform. In the context of classical optics, we implement discrete fractional Fourier transforms of exemplary wave functions and experimentally demonstrate the shift theorem. Moreover, we apply this approach in the quantum realm to Fourier transform separable and path-entangled biphoton wave functions. The proposed approach is versatile and could find applications in various fields where Fourier transforms are essential tools.

The key requirement for harnessing the quantum properties of light is the capability to detect and count individual photons. Of particular interest are photon-number-resolving detectors, which allow one to determine whether a state of light is classical or genuinely quantum. Existing schemes for addressing this challenge rely on a proportional conversion of photons to electrons. As such, they are capable of correctly characterizing small photon fluxes, yet are limited by uncertainties in the conversion rate. In this work, we employ a divide-and-conquer approach to infallibly discerning non-classicality of states of light. This is achieved by transforming the incident fields into uniform spatial distributions that readily lend themselves for characterization by standard on-off detectors. Since the exact statistics of the light stream in multiplexed on-off detectors are click statistics, our technique is freely scalable to accommodate-in principle-arbitrarily large photon fluxes. Our experiments pave the way towards genuine integrated photon-number-resolving detection for advanced on-chip photonic quantum networks.

Bloch oscillations of quantum particles manifest themselves as periodic spreading and relocalization of the associated wave functions when traversing lattice potentials subject to external gradient forces. Albeit this phenomenon is deeply rooted into the very foundations of quantum mechanics, all experimental observations so far have only contemplated dynamics of one and two particles initially prepared in separable local states. Evidently, a more general description of genuinely quantum Bloch oscillations will be achieved on excitation of a Bloch oscillator by nonlocal states. Here we report the observation of Bloch oscillations of two-particle N00N states, and discuss the nonlocality on the ground of Bell-like inequalities. The time evolution of two-photon N00N states in Bloch oscillators, whether symmetric, antisymmetric or partially symmetric, reveals transitions from particle antibunching to bunching. Consequently, the initial states can be tailored to produce spatial correlations akin to those of bosons, fermions and anyons, presenting potential applications in photonic quantum simulation.