3-year incidence and predictors of metabolic syndrome in schizophrenia in the national FACE-SZ cohort

AIMS

Metabolic Syndrome (MetS) is a major health epidemic of Western countries and patients with schizophrenia is a particularly vulnerable population due to lifestyle, mental illness and treatment factors. However, we lack prospective data to guide prevention. The aim of our study is then to determine MetS incidence and predictors in schizophrenia.

METHOD

Participants were recruited in 10 expert centers at a national level and followed-up for 3 years. MetS was defined according to the International Diabetes Federation criteria. Inverse probability weighting methods were used to correct for attrition bias.

RESULTS

Among the 512 participants followed-up for 3 years, 77.9% had at least one metabolic disturbance. 27.5% were identified with MetS at baseline and excluded from the analyses. Among the rest of participants (N = 371, mean aged 31.2 (SD = 9.1) years, with mean illness duration of 10.0 (SD = 7.6) years and 273 (73.6%) men), MetS incidence was 20.8% at 3 years and raised to 23.6% in tobacco smokers, 29.4% in participants receiving antidepressant prescription at baseline and 42.0% for those with 2 disturbed metabolic disturbances at baseline. Our multivariate analyses confirmed tobacco smoking and antidepressant consumption as independent predictors of MetS onset (adjusted odds ratios (aOR) = 3.82 [1.27-11.45], p = 0.016, and aOR = 3.50 [1.26-9.70], p = 0.0158). Antidepressant prescription predicted more specifically increased lipid disturbances and paroxetine was associated with the highest risk of MetS onset.

CONCLUSION

These results are an alarm call to prioritize MetS prevention and research in schizophrenia. We have listed interventions that should be actively promoted in clinical practice.

Decoherence of V[Formula: see text] spin defects in monoisotopic hexagonal boron nitride

Spin defects in hexagonal boron nitride (hBN) are promising quantum systems for the design of flexible two-dimensional quantum sensing platforms. Here we rely on hBN crystals isotopically enriched with either 10B or 11B to investigate the isotope-dependent properties of a spin defect featuring a broadband photoluminescence signal in the near infrared. By analyzing the hyperfine structure of the spin defect while changing the boron isotope, we first confirm that it corresponds to the negatively charged boron-vacancy center ([Formula: see text]). We then show that its spin coherence properties are slightly improved in 10B-enriched samples. This is supported by numerical simulations employing cluster correlation expansion methods, which reveal the importance of the hyperfine Fermi contact term for calculating the coherence time of point defects in hBN. Using cross-relaxation spectroscopy, we finally identify dark electron spin impurities as an additional source of decoherence. This work provides new insights into the properties of [Formula: see text] spin defects, which are valuable for the future development of hBN-based quantum sensing foils.

The impact of parent history of severe mental illness on schizophrenia outcomes: results from the real-world FACE-SZ cohort

Parent history of severe mental illness (PHSMI) may have long-term consequences in adult offspring due to genetic and early environmental factors in preliminary studies. To compare the outcomes associated in subjects with PHSMI to those in patients without PHSMI. The participants with schizophrenia and schizoaffective disorders were recruited in the ongoing FACE-SZ cohort at a national level (10 expert centers) and evaluated with a 1-day-long standardized battery of clinician-rated scales and patient-reported outcomes. PHSMI was defined as history of schizophrenia or bipolar disorders in at least one parent and was included as explanatory variable in multivariate models. Of the 724 included patients, 78 (10.7%) subjects were classified in the PHSMI group. In multivariate analyses, PHSMI patients had a better insight into schizophrenia and the need for treatment and reported more often childhood trauma history compared to patients without PHSMI. More specifically, those with paternal history of SMI reported more severe outcomes (increased childhood physical and emotional abuses, comorbid major depression and psychiatric hospitalizations). PHSMI is associated with increased risk of childhood trauma, major depressive disorder and psychiatric hospitalization and better insight in individuals with schizophrenia. Specific public health prevention programs for parents with SMI should be developed to help protect children from pejorative psychiatric outcomes. PHSMI may also explain in part the association between better insight and increased depression in schizophrenia.

Wildlife is imperiled in peri-urban landscapes: threats to arboreal mammals

Urbanization and deforestation impose severe challenges to wildlife, particularly for forest-living vertebrates. Understanding how the peri-urban matrix impacts their survival is critical for designing strategies to promote their conservation. We investigated the threats faced by brown howler monkeys (Alouatta guariba clamitans) in peri-urban regions of Rio Grande do Sul (RS) and Santa Catarina (SC) states, southern Brazil, by compiling negative interaction events (hereafter NIE) reported over more than two decades. We assessed the major NIEs, their distribution among age-sex classes, and the predictors of NIE-related mortality. After 20+ years of monitoring, we compiled 540 NIEs (RS = 248 and SC = 292). Electrocution by power lines was the most frequent cause of death or injury (37%), followed by dog attack (34%), vehicle collision (17%), and human mistreatment (12%). The occurrence of lethal injuries ranged from 5% to 69% depending on the type of NIE and on which state it occurred in. The overall post-NIE mortality was 56%. Adults of both sexes were the most affected individuals in both study regions. The minimal adequate GLM model explained 83% of the variation in NIE-related mortality. State, NIE type, and age-sex class were the main predictors of mortality. Overall, mortality was lower in SC and higher among adult females than in the other classes. We found that the survival of brown howler monkeys in the forest-urban interface is constrained by both the urban infrastructure and the growing interactions with humans and domestic and stray dogs (Canis familiaris). We propose the placement of aerial bridges, road signs and speed bumps in areas of frequent animal crossing, the sterilization of stray dogs, and the sensitization of local inhabitants on the importance of respecting and protecting wildlife to reduce their NIEs with humans and domestic animals in the forest-urban interface.

Exploring the Atwood-number dependence of the highly nonlinear Rayleigh-Taylor instability regime in high-energy-density conditions

We experimentally study the late-time, highly nonlinear regime of the Rayleigh-Taylor instability in a decelerating phase. A series of laser-driven experiments is performed on the LULI2000 laser, in which the initial Atwood number is varied by adjusting the decelerating medium density. The high-power laser is used in a direct drive configuration to put into motion a solid target. Its rear side, which initially possesses a two-dimensional machined sinusoidal perturbations, expands and decelerates into a foam leading to a Rayleigh-Taylor unstable situation. The interface position and morphology are measured by time-resolved x-ray radiography. We develop a simple Atwood-dependent model describing the motion of the decelerating interface, from which its acceleration history is obtained. The measured amplitude of the instability, or mixing zone width, is then compared with late-time acceleration-dependent Rayleigh-Taylor instability models. The shortcomings of this classical model, when applied to high-energy-density conditions, are shown. This calls into question their uses for systems, where a shock wave is present, such as those found in laboratory astrophysics or in inertial confinement fusion.

KS01.5.A Allergic airway inflammation impacts tumor take and delays experimental glioblastoma progression

BACKGROUND

Numerous epidemiological studies have highlighted the protective role of immunoglobulin E-mediated allergic diseases on glioblastoma (GBM) susceptibility and prognosis. However, the mechanistic explanations behind these phenomena remain unexplored. Our objective was to set up a preclinical model and investigate the mechanisms underlying such protection to improve our understanding of the crosstalk between immune system and brain tumor development.

MATERIAL AND METHODS

A mouse model of allergic airway inflammation (AAI) induced by repeated nasal instillation of House Dust Mite extract was initiated before intracranial implantation of GL261 glioma cells, in both immunocompetent (C57BL/6) and immunodeficient (RAG-KO) mice. Tumor take and tumor growth were monitored by MRI. Central (microglia) and peripheral (spleen, bone marrow) immune cells were characterized by flow cytometry. The response of microglia was further assessed by RNA sequencing. Impact of candidate genes on patient survival was characterized by Cox regression analysis using data from TCGA and CGGA.

RESULTS

Following AAI induction in C57BL/6 mice, engraftment of GL261 cells in the brain was delayed and tumor growth rate was reduced. This correlated with an increase in survival of the mice and was accompanied by increased effector memory T-cells in the circulation. Of note, the survival benefit was lost in RAG-KO mice devoid of adaptive immunity. At the level of the brain, we observed enhanced secretion of TNFα and IL6 in microglia ex vivo. AAI induced a transcriptional reprogramming of microglia towards a pro-inflammatory-like state. We identified an allergy-related microglia gene signature that is associated with improved prognosis of glioma patients.

CONCLUSION

Our results demonstrate that AAI limits both tumor take and GBM progression in mice, providing a preclinical model to study the role of allergic inflammation in GBM susceptibility and prognosis, respectively. At the functional level, we identify a potentiation of microglial and adaptive anti-tumoral immunity. Further investigations are warranted to shed light on the reciprocal crosstalk between microglial reprogramming and peripheral immunity in the context of allergies and brain tumors.

Resonance Raman enhancement by the intralayer and interlayer electron-phonon processes in twisted bilayer graphene

Twisted bilayer graphene is a fascinating system due to the possibility of tuning the electronic and optical properties by controlling the twisting angle \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\theta$$\end{document}θ between the layers. The coupling between the Dirac cones of the two graphene layers gives rise to van Hove singularities (vHs) in the density of electronic states, whose energies vary with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\theta$$\end{document}θ. Raman spectroscopy is a fundamental tool to study twisted bilayer graphene (TBG) systems since the Raman response is hugely enhanced when the photons are in resonance with transition between vHs and new peaks appear in the Raman spectra due to phonons within the interior of the Brillouin zone of graphene that are activated by the Moiré superlattice. It was recently shown that these new peaks can be activated by the intralayer and the interlayer electron–phonon processes. In this work we study how each one of these processes enhances the intensities of the peaks coming from the acoustic and optical phonon branches of graphene. Resonance Raman measurements, performed in many different TBG samples with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\theta$$\end{document}θ between \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$4^{\circ }$$\end{document}4∘ and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$16^{\circ }$$\end{document}16∘ and using several different laser excitation energies in the near-infrared (NIR) and visible ranges (1.39–2.71 eV), reveal the distinct enhancement of the different phonons of graphene by the intralayer and interlayer processes. Experimental results are nicely explained by theoretical calculations of the double-resonance Raman intensity in graphene by imposing the momentum conservation rules for the intralayer and the interlayer electron–phonon resonant conditions in TBGs. Our results show that the resonant enhancement of the Raman response in all cases is affected by the quantum interference effect and the symmetry requirements of the double resonance Raman process in graphene.

Home vision monitoring in patients with maculopathy: Real-life study of the OdySight application

INTRODUCTION

The goal of the present study was to analyze the implementation and clinical efficacy of OdySight, a mobile medical application for the remote monitoring of patients with maculopathy.

MATERIALS AND METHODS

In all, 60 patients with edematous maculopathies receiving traditional clinical treatment (PRN or Treat & Extend) were provided with OdySight to detect changes in visual acuity from home. To determine both the feasibility and reliability of the application, its use by patients (both testing and game play), as well as the processing of alerts by the clinical team, were analyzed during the first year.

RESULTS

The female-to-male ratio was 3:2, with a mean age of 64 years. 52% of patients presented with age-related macular degeneration, 31% with high myopia, 11% with retinal vein occlusion, and 6% with diabetic maculopathy. The conversion rate (defined as the percentage of patients completing at least one test following prescription) and the nine-month retention rate (percentage of active patients) were 61% and 24% respectively. Patients aged 50 to 70 years and those whose use of the app included game play represent 75% of active patients at 9 months. The 22 active patients performed 483 visual acuity tests, completed 1,667 game sessions, and underwent 77 in-person consultations. During the trial period, the clinical team processed 19 alerts, on average in fewer than 6 days. Decreases in visual acuity were detected with a sensitivity of 92% and specificity of 99%.

DISCUSSION

The use of connected and mobile devices today is widespread, as is interest in mobile medical applications. Long-term treatments for maculopathies can be a difficult burden to bear, both for patients and healthcare practitioners. Overcoming the challenges associated with the successful remote detection of recurrences thus represents a significant opportunity for improving patient care. The implementation of novel digital tools requires the cooperation of the clinical team as a whole, to both inform and motivate patients. OdySight demonstrates satisfactory detection rates, thanks to reliable and reproducible home testing, and can thus serve as a supplementary tool for patients whose consultations are often spaced several months apart. Implementation can be nonetheless improved by facilitating alert processing, a goal which necessitates active adaptation of clinical practices. In general, active patients were very satisfied with this personalized service.

CONCLUSION

Improved medical support, plus the amusing nature of the tests and games, both bolster long-term use of the OdySight app. The application allows for the remote monitoring of changes in visual acuity and affords patients and practitioners an added level of protection, particularly during long intervals between treatments and at the end of a treatment course. To ensure proper implementation, clinics should focus on reinforcing and modernizing the clinical pathway, from patient intake to the injection room.

Nickel Catalyzed Olefin Oligomerization and Dimerization

Brought to life more than half a century ago and successfully applied for high-value petrochemical intermediates production, nickel-catalyzed olefin oligomerization is still a very dynamic topic, with many fundamental questions to address and industrial challenges to overcome. The unique and versatile reactivity of nickel enables the oligomerization of ethylene, propylene, and butenes into a wide range of oligomers that are highly sought-after in numerous fields to be controlled. Interestingly, both homogeneous and heterogeneous nickel catalysts have been scrutinized and employed to do this. This rare specificity encouraged us to interlink them in this review so as to open up opportunities for further catalyst development and innovation. An in-depth understanding of the reaction mechanisms in play is essential to being able to fine-tune the selectivity and achieve efficiency in the rational design of novel catalytic systems. This review thus provides a complete overview of the subject, compiling the main fundamental/industrial milestones and remaining challenges facing homogeneous/heterogeneous approaches as well as emerging catalytic concepts, with a focus on the last 10 years.

Measurement of the Spectral Shape of the β-Decay of ^{137}Xe to the Ground State of ^{137}Cs in EXO-200 and Comparison with Theory

We report on a comparison between the theoretically predicted and experimentally measured spectra of the first-forbidden nonunique β-decay transition ^{137}Xe(7/2^{-})→^{137}Cs(7/2^{+}). The experimental data were acquired by the EXO-200 experiment during a deployment of an AmBe neutron source. The ultralow background environment of EXO-200, together with dedicated source deployment and analysis procedures, allowed for collection of a pure sample of the decays, with an estimated signal to background ratio of more than 99 to 1 in the energy range from 1075 to 4175 keV. In addition to providing a rare and accurate measurement of the first-forbidden nonunique β-decay shape, this work constitutes a novel test of the calculated electron spectral shapes in the context of the reactor antineutrino anomaly and spectral bump.

Expanding the phenotype of mitochondrial disease: Novel pathogenic variant in ISCA1 leading to instability of the iron-sulfur cluster in the protein

We report a patient carrying a novel pathogenic variant p.(Tyr101Cys) in ISCA1 leading to MMDS type 5. He initially presented a psychomotor regression with loss of gait and language skills and a tetrapyramidal spastic syndrome. Biochemical analysis of patient fibroblasts revealed impaired lipoic acid synthesis and decreased activities of complex I and II of respiratory chain. While ISCA1 is involved in the mitochondrial machinery for iron-sulfur cluster biogenesis, these dysfunctions are secondary to impaired maturation of mitochondrial proteins containing the [4Fe-4S] clusters. Expression and purification of the human ISCA1 showed a decreased stability of the [2Fe-2S] cluster in the mutated protein.

Search for Neutrinoless Double-β Decay with the Complete EXO-200 Dataset

A search for neutrinoless double-β decay (0νββ) in ^{136}Xe is performed with the full EXO-200 dataset using a deep neural network to discriminate between 0νββ and background events. Relative to previous analyses, the signal detection efficiency has been raised from 80.8% to 96.4±3.0%, and the energy resolution of the detector at the Q value of ^{136}Xe 0νββ has been improved from σ/E=1.23% to 1.15±0.02% with the upgraded detector. Accounting for the new data, the median 90% confidence level 0νββ half-life sensitivity for this analysis is 5.0×10^{25}  yr with a total ^{136}Xe exposure of 234.1 kg yr. No statistically significant evidence for 0νββ is observed, leading to a lower limit on the 0νββ half-life of 3.5×10^{25}  yr at the 90% confidence level.

Rayleigh-Taylor instability experiments on the LULI2000 laser in scaled conditions for young supernova remnants

We describe a platform developed on the LULI2000 laser facility to investigate the evolution of Rayleigh-Taylor instability (RTI) in scaled conditions relevant to young supernova remnants (SNRs) up to 200 years. An RT unstable interface is imaged with a short-pulse laser-driven (PICO2000) x-ray source, providing an unprecedented simultaneous high spatial (24μm) and temporal (10 ps) resolution. This experiment provides relevant data to compare with astrophysical codes, as observational data on the development of RTI at the early stage of the SNR expansion are missing. A comparison is also performed with FLASH radiative magnetohydrodynamic simulations.

Characterization of high spatial resolution lithium fluoride X-ray detectors

The response of lithium fluoride (LiF) crystal detectors to monochromatic X-rays is measured in the multi-kilo-electron-volt range. This response, as a function of the X-ray dose, is independent of photon energy with no saturation level found. The response, as a function of the incident energy flux, is found to increase for photons of lower energy due to the differing attenuation lengths of X-ray photons within the crystal. Small differences are seen between different confocal microscopes used to scan the data, suggesting the need for absolute calibration. The spatial resolution of the LiF is also measured (1.19-1.36 μm) and is found to be independent of incident photon energy. Finally, a photometric study is performed in order to assess the feasibility of using these detectors at current X-ray free electron laser and laser facilities worldwide.

Laboratory study of stationary accretion shock relevant to astrophysical systems

Accretion processes play a crucial role in a wide variety of astrophysical systems. Of particular interest are magnetic cataclysmic variables, where, plasma flow is directed along the star’s magnetic field lines onto its poles. A stationary shock is formed, several hundred kilometres above the stellar surface; a distance far too small to be resolved with today’s telescopes. Here, we report the results of an analogous laboratory experiment which recreates this astrophysical system. The dynamics of the laboratory system are strongly influenced by the interplay of material, thermal, magnetic and radiative effects, allowing a steady shock to form at a constant distance from a stationary obstacle. Our results demonstrate that a significant amount of plasma is ejected in the lateral direction; a phenomenon that is under-estimated in typical magnetohydrodynamic simulations and often neglected in astrophysical models. This changes the properties of the post-shock region considerably and has important implications for many astrophysical studies.

Supersonic plasma turbulence in the laboratory

The properties of supersonic, compressible plasma turbulence determine the behavior of many terrestrial and astrophysical systems. In the interstellar medium and molecular clouds, compressible turbulence plays a vital role in star formation and the evolution of our galaxy. Observations of the density and velocity power spectra in the Orion B and Perseus molecular clouds show large deviations from those predicted for incompressible turbulence. Hydrodynamic simulations attribute this to the high Mach number in the interstellar medium (ISM), although the exact details of this dependence are not well understood. Here we investigate experimentally the statistical behavior of boundary-free supersonic turbulence created by the collision of two laser-driven high-velocity turbulent plasma jets. The Mach number dependence of the slopes of the density and velocity power spectra agree with astrophysical observations, and supports the notion that the turbulence transitions from being Kolmogorov-like at low Mach number to being more Burgers-like at higher Mach numbers.

X-ray backlighter requirements for refraction-based electron density diagnostics through Talbot-Lau deflectometry

Talbot-Lau x-ray interferometers can map electron density gradients in High Energy Density (HED) samples. In the deflectometer configuration, it can provide refraction, attenuation, elemental composition, and scatter information from a single image. X-ray backlighters in Talbot-Lau deflectometry must meet specific requirements regarding source size and x-ray spectra, amongst others, to accurately diagnose a wide range of HED experiments. 8 keV sources produced in the high-power laser and pulsed power environment were evaluated as x-ray backlighters for Talbot-Lau x-ray deflectometry. In high-power laser experiments, K-shell emission was produced by irradiating copper targets (500 × 500 × 12.5 μm³ foils, 20 μm diameter wire, and >10 μm diameter spheres) with 30 J, 8-30 ps laser pulses and a 25 μm copper wire with a 60 J, 10 ps laser pulse. In the pulsed power environment, single (2 × 40 μm) and double (4 × 25 μm) copper x-pinches were driven at ∼1 kA/ns. Moiré fringe formation was demonstrated for all x-ray sources explored, and detector performance was evaluated for x-ray films, x-ray CCDs, and imaging plates in context of spatial resolution, x-ray emission, and fringe contrast.

Mathematical modeling of the proliferation gradient in multicellular tumor spheroids

MultiCellular Tumor Spheroids are 3D cell cultures that can accurately reproduce the behavior of solid tumors. It has been experimentally observed that large spheroids exhibit a decreasing gradient of proliferation from the periphery to the center of these multicellular 3D models: the proportion of proliferating cells is higher in the periphery while the non-proliferating quiescent cells increase in depth. In this paper, we propose to investigate the key mechanisms involved in the establishment of this gradient with a Partial Differential Equations model that mimics the experimental set-up of growing spheroids under different nutrients supply conditions. The model consists of mass balance equations on the two cell populations observed in the data: the proliferating cells and the quiescent cells. The spherical symmetry is used to rewrite the model in radial and relative coordinates. Thanks to a rigorous data postprocessing the model is then fit and compared quantitatively with the experimental quantification of the percentage of proliferating cells from EdU immunodetection on 2D spheroid cryosection images. The results of this calibration show that the proliferation gradient observed in spheroids can be quantitatively reproduced by our model.

Isotope engineering of van der Waals interactions in hexagonal boron nitride

Hexagonal boron nitride is a model lamellar compound where weak, non-local van der Waals interactions ensure the vertical stacking of two-dimensional honeycomb lattices made of strongly bound boron and nitrogen atoms. We study the isotope engineering of lamellar compounds by synthesizing hexagonal boron nitride crystals with nearly pure boron isotopes (¹⁰B and ¹¹B) compared to those with the natural distribution of boron (20 at% ¹⁰B and 80 at% ¹¹B). On the one hand, as with standard semiconductors, both the phonon energy and electronic bandgap varied with the boron isotope mass, the latter due to the quantum effect of zero-point renormalization. On the other hand, temperature-dependent experiments focusing on the shear and breathing motions of adjacent layers revealed the specificity of isotope engineering in a layered material, with a modification of the van der Waals interactions upon isotope purification. The electron density distribution is more diffuse between adjacent layers in ¹⁰BN than in ¹¹BN crystals. Our results open perspectives in understanding and controlling van der Waals bonding in layered materials.

[Follow-up of postoperative endophthalmitis after cataract surgery and intravitreal injection of drugs - an analysis since 2009]

BACKGROUND

The frequency of intravitreal injection of drugs (IVI) has significantly increased recently and it is performed like cataract surgery as an outpatient procedure. The occurrence of postoperative endophthalmitis is rare, only few data of multicentre studies are available.

METHODS

We analysed the data of 30 consecutive patients with endophthalmitis following cataract surgery (group 1, n = 20) and IVI (group 2, n = 10) requiring therapy in a referral eye clinic from January 2009 to December 2013. All patients received topical and systemic anti-inflammatory and anti-infective therapy. Due to vitreous opacification and severe loss of vision 83 % of the eyes underwent immediately pars plana vitrectomy with diagnostic microbiological probe and intravitreal application of vancomycin and gentamicin.

RESULTS

Endophthalmitis occurred independently in both groups 1 to 10 days, on average 4 days, postoperatively. Group 1 showed conjunctival infection in 80 % (n = 16), group 2 in 20 % (n = 2). Hypopyon was found in group 1 in 65 % (n = 13), in group 2 in 40 % (n = 4). Group 1 presented retinal haemorrhages and epiretinal fibrin membranes in 15 % (n = 3), group 2 in 70 % (n = 7). Vitreous cultures were positive in 80 % (vancomycin-sensitive staphylococci). Staphylococcus was the most frequent bacteria, resistant to ceftazidime. In group 1 visual acuity was initially in 65 % (n = 13) of the eyes < 20/400 or worse, in group 2 90 % (n = 9) of the eyes had hand motions and in 10 % (n = 1) worse than 20/400. Visual outcome was 20/30 on average for group 1, PVR retinal detachment occurred once. In group 2 no patient achieved better visual outcome than < 20/400, 40 % of the eyes required permanent silicon oil tamponade because of PVR retinal detachment. The major pathogens were staphylococci resistant to ceftazidim.

CONCLUSION

Endophthalmitis following IVI had poor visual outcome compared to endophthalmitis following cataract surgery and showed less anterior segment symptoms.

Experimental evidence of a mechanical coupling between layers in an individual double-walled carbon nanotube

We perform transmission electron microscopy, electron diffraction, and Raman scattering experiments on an individual suspended double-walled carbon nanotube (DWCNT). The first two techniques allow the unambiguous determination of the DWCNT structure: (12,8)@(16,14). However, the low-frequency features in the Raman spectra cannot be connected to the derived layer diameters d by means of the 1/d power law, widely used for the diameter dependence of the radial-breathing mode of single-walled nanotubes. We discuss this disagreement in terms of mechanical coupling between the layers of the DWCNT, which results in collective vibrational modes. Theoretical predictions for the breathing-like modes of the DWCNT, originating from the radial-breathing modes of the layers, are in a very good agreement with the observed Raman spectra. Moreover, the mechanical coupling qualitatively explains the observation of Raman lines of breathing-like modes, whenever only one of the layers is in resonance with the laser energy.

Raman active phonons of identified semiconducting single-walled carbon nanotubes

The resonant Raman spectra of (n, m) semiconducting single-walled carbon nanotubes, unambiguously identified from their electron diffraction patterns, have been measured. The diameter dependence of the frequency of the tangential modes with A symmetry has been obtained in the diameter range from 1.4 to 2.5 nm. The comparison between the excitation energies and the calculated transition energies allowed us to determine precisely the values of the Es33 and Es44 transition energies. Finally, in the debate concerning the dominant process at the origin of the first-order Raman scattering in single-walled carbon nanotubes (single resonance process or double resonance process), our results are well understood in the framework of a single resonance process.

Potency and sterility of anesthetic drugs in obstetric anesthesia

In order to estimate how long a medication can remain prepared before the integrity or concentration of the drug is compromised, we assessed the sterility and potency of medications commonly used in our obstetric anesthesia practice. Our goal was to evaluate the following drugs over a 30-day period: epinephrine, atropine, lidocaine, succinylcholine, and ephedrine. The medications were prepared by various medical staff, drawn into sterile plastic syringes and left at room temperature unprotected from light for the duration of the study. The syringes were collected daily, stored and randomly sampled after 7, 14, 21 and 30 days by research personnel. Potency and sterility of atropine, ephedrine and lidocaine were maintained over the study period. Succinylcholine and epinephrine could not be assayed but the solutions remained sterile for 30 and 14 days respectively. Data were incomplete for epinephrine. These findings suggest that some drugs that are commonly used in obstetric anesthesia are stable for long periods of time. Modification of current standards of practice could result in a significant reduction in drug waste and therefore cost.