Involvement of the JAK-STAT pathway in the molecular landscape of tyrosine kinase fusion-negative hypereosinophilic syndromes: A nationwide CEREO study

We investigated using a custom NGS panel of 149 genes the mutational landscape of 64 consecutive adult patients with tyrosine kinase fusion-negative hypereosinophilia (HE)/hypereosinophilic syndrome (HES) harboring features suggestive of myeloid neoplasm. At least one mutation was reported in 50/64 (78%) patients (compared to 8/44 (18%) patients with idiopathic HE/HES/HEUS used as controls; p < .001). Thirty-five patients (54%) had at least one mutation involving the JAK-STAT pathway, including STAT5B (n = 18, among which the hotspot N642H, n = 13), JAK1 (indels in exon 13, n = 5; V658F/L, n = 2), and JAK2 (V617F, n = 6; indels in exon 13, n = 2). Other previously undescribed somatic mutations were also found in JAK2, JAK1, STAT5B, and STAT5A, including three patients who shared the same STAT5A V707fs mutation and features consistent with primary polycythemia. Nearly all JAK-STAT mutations were preceded by (or associated with) myelodysplasia-related gene mutations, especially in RNA-splicing genes or chromatin modifiers. In multivariate analysis, neurologic involvement (hazard ratio [HR] 4.95 [1.87-13.13]; p = .001), anemia (HR 5.50 [2.24-13.49]; p < .001), and the presence of a high-risk mutation (as per the molecular international prognosis scoring system: HR 6.87 [2.39-19.72]; p < .001) were independently associated with impaired overall survival. While corticosteroids were ineffective in all treated JAK-STAT-mutated patients, ruxolitinib showed positive hematological responses including in STAT5A-mutated patients. These findings emphasize the usefulness of NGS for the workup of tyrosine kinase fusion-negative HE/HES patients and support the use of JAK inhibitors in this setting. Updated classifications could consider patients with JAK-STAT mutations and eosinophilia as a new "gene mutated-entity" that could be differentiated from CEL, NOS, and idiopathic HES.

Van der Waals Epitaxy of Weyl-Semimetal T-WTe2

Epitaxial growth of WTe2 offers significant advantages, including the production of high-quality films, possible long-range in-plane ordering, and precise control over layer thicknesses. However, the mean island size of WTe2 grown by molecular beam epitaxy (MBE) in the literature is only a few tens of nanometers, which is not suitable for the implementation of devices at large lateral scales. Here we report the growth of Td -WTe2 ultrathin films by MBE on monolayer (ML) graphene, reaching a mean flake size of ≃110 nm, which is, on overage, more than three times larger than previous results. WTe2 films thicker than 5 nm have been successfully synthesized and exhibit the expected Td phase atomic structure. We rationalize the epitaxial growth of Td-WTe2 and propose a simple model to estimate the mean flake size as a function of growth parameters that can be applied to other transition metal dichalcogenides (TMDCs). Based on nucleation theory and the Kolmogorov-Johnson-Meh-Avrami (KJMA) equation, our analytical model supports experimental data showing a critical coverage of 0.13 ML above which WTe2 nucleation becomes negligible. The quality of monolayer WTe2 films is demonstrated by electronic band structure analysis using angle-resolved photoemission spectroscopy (ARPES), which is in agreement with first-principles calculations performed on free-standing WTe2 and previous reports. We found electron pockets at the Fermi level, indicating a n-type doping of WTe2 with an electron density of n = 2.0 ± 0.5 × 1012 cm-2 for each electron pocket.

ATYPICAL FOVEAL AND PARAFOVEAL ABNORMALITIES IN SICKLE CELL DISEASE

PURPOSE

The primary aim was to describe the patterns of paramacular involvement, not yet reported but that optical coherence tomography angiography can now detect in patients with sickle cell disease. The secondary aim was to search arguments concerning the physiopathogeny of paramacular involvement.

METHODS

This institutional cohort retrospective study was conducted in a Referral Center for Ophthalmological Rare Diseases. Follow-up included an ophthalmologic examination with optical coherent tomography and optical coherent tomography angiography.

RESULTS

One hundred and thirty-two patients with SCD were included. Typical sickle cell maculopathy was observed in temporal area in 84 eyes (40.0%) of SS patients and eight eyes (14.8%) of SC patients ( P < 0.001). Enlargement of the foveal avascular zone was observed in 10 eyes of eight SS patients. Two atypical parafoveal abnormalities were found in SS patients only. The first one consisted of macular thinning with normal vascularization in 15 eyes of 11 patients. The second atypical maculopathy was large areas of loss of vascularization without retinal thinning 10 eyes of six patients. Multivariate analysis did not show a statistically significant relation between the peripheral sickle retinopathy stage and the different type of sickle cell maculopathy ( P = 0.21).

CONCLUSION

Those atypical sickle cell maculopathy may correspond to early forms preceding a typical sickle cell disease maculopathy (SCDM). This would point toward several physiopathogenic mechanisms. The first one included the existence of ischemia that can be related to anemia. Presence of retinal thinning without vascular involvement point out to a neurogenic mechanism.

Giant Atomic Swirl in Graphene Bilayers with Biaxial Heterostrain

The study of moiré engineering started with the advent of van der Waals heterostructures, in which stacking 2D layers with different lattice constants leads to a moiré pattern controlling their electronic properties. The field entered a new era when it was found that adjusting the twist between two graphene layers led to strongly-correlated-electron physics and topological effects associated with atomic relaxation. A twist is now routinely used to adjust the properties of 2D materials. This study investigates a new type of moiré superlattice in bilayer graphene when one layer is biaxially strained with respect to the other-so-called biaxial heterostrain. Scanning tunneling microscopy measurements uncover spiraling electronic states associated with a novel symmetry-breaking atomic reconstruction at small biaxial heterostrain. Atomistic calculations using experimental parameters as inputs reveal that a giant atomic swirl forms around regions of aligned stacking to reduce the mechanical energy of the bilayer. Tight-binding calculations performed on the relaxed structure show that the observed electronic states decorate spiraling domain wall solitons as required by topology. This study establishes biaxial heterostrain as an important parameter to be harnessed for the next step of moiré engineering in van der Waals multilayers.

Relationship between paramacular thinning, cerebral vasculopathy, and hematological risk factors in sickle cell disease

Purpose

To identify risk factors for sickle cell maculopathy due to hematological parameters (especially anemia and hemolysis) or cerebral vasculopathy.

Methods

This retrospective study was conducted at a Referral Center. The follow-up included optical coherent tomography/optical coherent tomography angiography, neuro-radiological imaging, and a hematological assessment (hemoglobin, hemoglobin S level, reticulocytes, mean corpuscular volume, bilirubin, and lactate dehydrogenase).

Results

Hundred and thirty-two sickle cell patients were included. Maculopathy was observed in 127 eyes of SS patients and 10 eyes of SC patients (p < 0.001), unrelated to peripheral retinopathy. Cerebral vasculopathy was more frequent in SS patients (p < 0.001) and was also associated with the presence of maculopathy (p = 0.049), and it was related to peripheral retinopathy (p < 0.001). All biological parameters significantly differed according to the genotype (p < 0.001) but not according to the presence of cerebral vasculopathy or maculopathy. In the multivariate analysis, reticulocytes and bilirubin were associated with the presence of cerebral vasculopathy and maculopathy.

Conclusion

The data obtained were consistent with the role of anemia or hemolysis markers in cerebral vasculopathy and macular involvement. As a trend of hemolysis appears to be a risk factor for these complications, this validates the use of preventive plasmapheresis in these patients.

Descriptor engineering in machine learning regression of electronic structure properties for 2D materials

We build new material descriptors to predict the band gap and the work function of 2D materials by tree-based machine-learning models. The descriptor's construction is based on vectorizing property matrices and on empirical property function, leading to mixing features that require low-resource computations. Combined with database-based features, the mixing features significantly improve the training and prediction of the models. We find R[Formula: see text] greater than 0.9 and mean absolute errors (MAE) smaller than 0.23 eV both for the training and prediction. The highest R[Formula: see text] of 0.95, 0.98 and the smallest MAE of 0.16 eV and 0.10 eV were obtained by using extreme gradient boosting for the bandgap and work-function predictions, respectively. These metrics were greatly improved as compared to those of database features-based predictions. We also find that the hybrid features slightly reduce the overfitting despite a small scale of the dataset. The relevance of the descriptor-based method was assessed by predicting and comparing the electronic properties of several 2D materials belonging to new classes (oxides, nitrides, carbides) with those of conventional computations. Our work provides a guideline to efficiently engineer descriptors by using vectorized property matrices and hybrid features for predicting 2D materials properties via ensemble models.

Acute chest syndrome in adult patients with sickle cell disease: The relationship with the time to onset after hospital admission

Data on acute chest syndrome (ACS) in adult sickle cell disease patients are scarce. In this study, we describe 105 consecutive ACS episodes in 81 adult patients during a 32-month period and compare the characteristics as a function of the time to onset after hospital admission for a vaso-occlusive crisis (VOC), that is early-onset episodes (time to onset ≤24 h, 42%) versus secondary episodes (>24 h, 58%; median [interquartile range] time to onset: 2 [2-3] days). The median age was 27 [22-34] years, 89% of the patients had an S/S or S/β⁰ -thalassaemia genotype; 81% of the patients had a history of ACS (median: 3 [2-5] per patient), only 61% were taking a disease-modifying treatment at the time of the ACS. Fever and chest pain were noted in respectively 54% and 73% of the episodes. Crackles (64%) and bronchial breathing (32%) were the main abnormal auscultatory findings. A positive microbiological test was found for 20% of episodes. Fifty percent of the episodes required a blood transfusion; ICU transfer and mortality rates were respectively 29% and 1%. Secondary and early-onset forms of ACS did not differ significantly. Disease-modifying treatments should be revaluated after each ACS episode because the recurrence rate is high.

Structural identification of graphene films and nanoislands on 6H-SiC(0001) by direct height measurement

By combining non-contact atomic force microscopy (nc-AFM) and Kelvin probe microscopy (KPFM) in ultra high vacuum environment (UHV), we directly measure the height and work function of graphene monolayer on the Si-face of 6H-SiC(0001) with a precision that allows us to differentiate three different types of graphene structures : zero layer graphene (ZLG), Quasi free-standing monolayer graphene (QFMLG) and bilayer graphene (BLG). The height and work function of ZLG are 2.62 ± 0.22 Å and 4.42 ± 0.05 eV respectively, when they are 4.09 ± 0.11 Å and 4.63 ± 0.05 eV for QFMLG. The work function is 4.83 ± 0.05 eV for the BLG. Unlike any other available technique, the local nc-AFM/KPFM dual probe makes it possible to directly identify the nature of nanometer-sized graphene islands that constitute the early nuclei of graphene monolayer grown on 6H-SiC(0001) by chemical vapor deposition.

Transbronchial cryobiopsy proven amyloid diffuse cystic lung disease complicating a transthyretin mutated (ATTRm) amyloidosis: a case report

We present a case report of transbronchial cryobiopsy proven diffuse amyloid cystic lung disease complicating a homozygous Val122Ile (V122I) transthyretin mutated amyloidosis (ATTRm). To the best of our knowledge, this is the first case in the literature reporting such pulmonary lesions in ATTRm amyloidosis, and notably diagnosed through cryobiopsy. A 51-year-old man from Mali with a past medical history of bilateral carpal tunnel syndrome presented erectile dysfunction, asthenia and worsening dyspnoea over the past year. He presented signs of cardiac failure; histological and radiological investigations diagnosed cardiac amyloidosis. He was found homozygote for the V122I mutation in transthyretin. A diffuse cystic lung disease (DCLD) was noted on computed tomography (CT) scan. We performed a transbronchial pulmonary cryobiopsy that revealed histological transthyretin amyloid deposits. This case report illustrates the safety and usefulness of cryobiopsy in the setting of DCLD and extends ATTRm amyloidosis as a possible cause of DCLD.

Crystalline Quality and Surface Morphology Improvement of Face-to-Face Annealed MBE-Grown AlN on h-BN

In this study, AlN epilayers were grown by ammonia-assisted molecular beam epitaxy on 3 nm h-BN grown on c-sapphire substrates. Their structural properties were investigated by comparing as-grown and postgrowth annealed layers. The role of annealing on the crystalline quality and surface morphology was studied as a function of AlN thickness and the annealing duration and temperature. Optimum annealing conditions were identified. The results of X-ray diffraction showed that optimization of the annealing recipe led to a significant reduction in the symmetric (0 0 0 2) and skew symmetric (1 0 -1 1) reflections, which was associated with a reduction in edge and mixed threading dislocation densities (TDDs). Furthermore, the impact on the crystalline structure of AlN and its surface was studied, and the results showed a transition from a surface with high roughness to a smoother surface morphology with a significant reduction in roughness. In addition, the annealing duration was increased at 1650 °C to further understand the impact on both AlN and h-BN, and the results showed a diffusion interplay between AlN and h-BN. Finally, an AlN layer was regrown on the top of an annealed template, which led to large terraces with atomic steps and low roughness.

Van der Waals Heteroepitaxy of Air-Stable Quasi-Free-Standing Silicene Layers on CVD Epitaxial Graphene/6H-SiC

Graphene, consisting of an inert, thermally stable material with an atomically flat, dangling-bond-free surface, is by essence an ideal template layer for van der Waals heteroepitaxy of two-dimensional materials such as silicene. However, depending on the synthesis method and growth parameters, graphene (Gr) substrates could exhibit, on a single sample, various surface structures, thicknesses, defects, and step heights. These structures noticeably affect the growth mode of epitaxial layers, e.g., turning the layer-by-layer growth into the Volmer-Weber growth promoted by defect-assisted nucleation. In this work, the growth of silicon on chemical vapor deposited epitaxial Gr (1 ML Gr/1 ML Gr buffer) on a 6H-SiC(0001) substrate is investigated by a combination of atomic force microscopy (AFM), scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and Raman spectroscopy measurements. It is shown that the perfect control of full-scale almost defect-free 1 ML Gr with a single surface structure and the ultraclean conditions for molecular beam epitaxy deposition of silicon represent key prerequisites for ensuring the growth of extended silicene sheets on epitaxial graphene. At low coverages, the deposition of Si produces large silicene sheets (some hundreds of nanometers large) attested by both AFM and SEM observations and the onset of a Raman peak at 560 cm^-1, very close to the theoretical value of 570 cm^-1 calculated for free-standing silicene. This vibrational mode at 560 cm^-1 represents the highest ever experimentally measured value and is representative of quasi-free-standing silicene with almost no interaction with inert nonmetal substrates. From a coverage rate of 1 ML, the silicene sheets disappear at the expense of 3D Si dendritic islands whose density, size, and thickness increase with the deposited thickness. From this coverage, the Raman mode assigned to quasi-free-standing silicene totally vanishes, and the 2D flakes of silicene are no longer observed by AFM. The experimental results are in very good agreement with the results of kinetic Monte Carlo simulations that rationalize the initial flake growth in solid-state dewetting conditions, followed by the growth of ridges surrounding and eventually covering the 2D flakes. A full description of the growth mechanism is given. This study, which covers a wide range of growth parameters, challenges recent results stating the impossibility to grow silicene on a carbon inert surface and is very promising for large-scale silicene growth. It shows that silicene growth can be achieved using perfectly controlled and ultraclean deposition conditions and an almost defect-free Gr substrate.

Neurological complications of varicella zoster virus reactivation: Prognosis, diagnosis, and treatment of 72 patients with positive PCR in the cerebrospinal fluid

BACKGROUND

VZV infection can involve every level of the neurologic system: from the central nervous system (CNS) to the peripheral nervous system (PNS), including aseptic meningitis. Prognosis seems to differ between these neurological involvements. Prognostic factors remain unknown.

METHODS

This is a retrospective multicenter study including all patients with a positive VZV polymerase chain reaction (PCR) in the cerebrospinal fluid (CSF) from eight centers in Paris (France) between 2011 and 2018. Unfavorable outcome was defined as mortality linked to VZV or incomplete recovery. Modified Rankin Scale (mRS) evaluated disability before and after the infection, with the difference designated as Rankin Delta.

RESULTS

Seventy-two patients were included (53% male, median age 51 years, median mRS 0). Immunosuppression was reported in 42%. The clinical spectrum included 26 cases of meningitis, 27 instances of CNS involvement, 16 of PNS involvement, and 3 isolated replications (positive PCR but no criteria for neurological complications from VZV). Antiviral treatment was administered to 69 patients (96%). Sixty-two patients completed follow-up. Death linked to VZV occurred in eight cases. Unfavorable outcome (UO) occurred in 60% and was significantly associated with a higher prior mRS (Odd-ratio (OR) 3.1 [1.4-8.8] p = .012) and the presence of PNS or CNS manifestations (OR 22 [4-181] p = .001, OR 6.2 [1.3-33] p = .03, respectively, compared to meningitis). In the CSF, higher protein level (p < .0001) was also significantly associated with a higher Rankin Delta.

CONCLUSIONS

Neurological complications of VZV with evidence of CSF viral replication are heterogeneous: aseptic meningitis has a good prognosis, whereas presence of CNS and PNS involvement is associated with a higher risk of mortality and of sequelae, respectively.

Sarilumab in adults hospitalised with moderate-to-severe COVID-19 pneumonia (CORIMUNO-SARI-1): An open-label randomised controlled trial

Background

Patients with COVID-19 pneumonia can have increased inflammation and elevated cytokines, including interleukin (IL)-6, which might be deleterious. Thus, sarilumab, a high-affinity anti-IL-6 receptor antibody, might improve the outcome of patients with moderate-to-severe COVID-19 pneumonia.

Methods

We did a multicentric, open-label, Bayesian randomised, adaptive, phase 2/3 clinical trial, nested within the CORIMUNO-19 cohort, to test a superiority hypothesis. Patients 18 years or older hospitalised with COVID-19 in six French centres, requiring at least 3L/min of oxygen but without ventilation assistance and a WHO Clinical Progression Scale [CPS] score of 5 were enrolled. Patients were randomly assigned (1:1) via a web-based system, according to a randomisation list stratified on centre and with blocks randomly selected among 2 and 4, to receive usual care plus 400 mg of sarilumab intravenously on day 1 and on day 3 if clinically indicated (sarilumab group) or usual care alone (usual care group). Primary outcomes were the proportion of patients with WHO-CPS scores greater than 5 on the 10-point scale on day 4 and survival without invasive or non-invasive ventilation at day 14. This completed trial is closed to new participants and is registered with ClinicalTrials.gov, NCT04324073.

Findings

165 patients were recruited from March 27 to April 6, 2020, and 148 patients were randomised (68 patients to the sarilumab group and 80 to the usual care group) and followed up for 90 days. Median age was 61·7 years [IQR 53·0–71·1] in the sarilumab group and 62·8 years [56·0–71·7] in the usual care group. In the sarilumab group 49 (72%) of 68 were men and in the usual care group 59 (78%) of 76 were men. Four patients in the usual care group withdrew consent and were not analysed. 18 (26%) of 68 patients in the sarilumab group had a WHO-CPS score greater than 5 at day 4 versus 20 (26%) of 76 in the usual care group (median posterior absolute risk difference 0·2%; 90% credible interval [CrI] −11·7 to 12·2), with a posterior probability of absolute risk difference greater than 0 of 48·9%. At day 14, 25 (37%) patients in the sarilumab and 26 (34%) patients in the usual care group needed ventilation or died, (median posterior hazard ratio [HR] 1·10; 90% CrI 0·69–1·74) with a posterior probability HR greater than 1 of 37·4%. Serious adverse events occurred in 27 (40%) patients in the sarilumab group and 28 (37%) patients in the usual care group (p=0·73).

Interpretation

Sarilumab treatment did not improve early outcomes in patients with moderate-to-severe COVID-19 pneumonia. Further studies are warranted to evaluate the effect of sarilumab on long-term survival.

Funding

Assistance publique—Hôpitaux de Paris

Nanoscale structural and electrical properties of graphene grown on AlGaN by catalyst-free chemical vapor deposition

The integration of graphene (Gr) with nitride semiconductors is highly interesting for applications in high-power/high-frequency electronics and optoelectronics. In this work, we demonstrated the direct growth of Gr on Al_0.5Ga_0.5N/sapphire templates by propane (C₃H₈) chemical vapor deposition at a temperature of 1350 °C. After optimization of the C₃H₈ flow rate, a uniform and conformal Gr coverage was achieved, which proved beneficial to prevent degradation of AlGaN morphology. X-ray photoemission spectroscopy revealed Ga loss and partial oxidation of Al in the near-surface AlGaN region. Such chemical modification of a ∼2 nm thick AlGaN surface region was confirmed by cross-sectional scanning transmission electron microscopy combined with electron energy loss spectroscopy, which also showed the presence of a bilayer of Gr with partial sp²/sp³ hybridization. Raman spectra indicated that the deposited Gr is nanocrystalline (with domain size ∼7 nm) and compressively strained. A Gr sheet resistance of ∼15.8 kΩ sq^-1 was evaluated by four-point-probe measurements, consistently with the nanocrystalline nature of these films. Furthermore, nanoscale resolution current mapping by conductive atomic force microscopy indicated local variations of the Gr carrier density at a mesoscopic scale, which can be ascribed to changes in the charge transfer from the substrate due to local oxidation of AlGaN or to the presence of Gr wrinkles.

Central serous chorioretinopathy and antiphospholipid syndrome: Three cases report

Antiphospholipid syndrome (APS) is an acquired autoimmune disease characterized by recurrent venous or arterial thrombotic events and pregnancy morbidity, with persistently presence of antiphospholipid antibodies (aPL). We report three cases of central serous chorioretinopathy (CSC) associated with APS.

InGaN islands and thin films grown on epitaxial graphene

In this work, the growth of InGaN on epitaxial graphene by molecular beam epitaxy is studied. The nucleation of the alloy follows a three-dimensional (3D) growth mode in the observed temperature range of 515 °C-765 °C, leading to the formation of dendrite-like islands. Careful Raman scattering experiments show that the graphene underneath is not degraded by the InGaN growth. Moreover, lateral displacement of the nuclei during an atomic force microscopy (AFM) scan demonstrates weak bonding interactions between the InGaN and the graphene. Finally, a longer growth time of the alloy gives rise to a compact thin film in a partial epitaxial relationship with the SiC underneath the graphene.

[Pituitary apoplexy following coronary bypass surgery: A case report and literature review]

INTRODUCTION

Pituitary apoplexy is a >rare entity that presents with a sudden onset of headache associated with visual and endocrinological disturbances due to pituitary hemorrhage or infarction. It usually occurs in patients with an unknown pituitary adenoma. Cardiac surgery, and especially coronary artery bypass grafting, can be a precipitating factor in these patients.

CASE REPORT

We report an 82-year-old male patient who presented with sudden headache and delirium, a right sixth cranial nerve palsy, a right temporal hemianopsia, and a severe loss of left eye visual acuity in the immediate post-operative course of a coronary artery bypass surgery. Pituitary apoplexy was demonstrated on both MRI and CT-scan. Trans-sphenoidal surgical decompression was performed 13 days after coronary artery bypass grafting, with immediate beneficial effect on the delirium and a partial recovery of visual disturbances.

CONCLUSION

Pituitary apoplexy is a rare and life-threatening complication that may occur after cardiac surgery (coronary artery bypass, cardiac valve surgery), often precipitated by the use of cardiopulmonary bypass. It can occur after other surgical procedures (orthopedic, digestive, thoracic). The diagnosis must be considered during the early postoperative period in the presence of unusual and severe headache associated with visual disturbances.

[Botulism: A case report and literature review]

INTRODUCTION

Botulism is a rare syndrome resulting from the action of a neurotoxin produced by Clostridium botulinum, that it is potentially life threatening if diagnosis is delayed.

CASE REPORT

We report a 26-year-old woman who presented an acute onset of bilateral cranial neuropathies associated with an anticholinergic syndrome in the absence fever leading to consider and confirm the diagnosis of botulism. At the end of follow-up, 7 weeks later, the outcome was favorable with an almost complete neurologic recovery.

CONCLUSION

Although botulism is uncommon, better awareness of its manifestations and high clinical suspicion should shorten diagnostic delay that makes the use of specific antitoxin ineffective. An acute onset of a bilateral oculomotor palsy, a fixed pupillary dilation and descending weakness in the absence of fever is typical of botulism. Outcome is usually favorable with a slow but full neurological recovery.

Remote epitaxy using graphene enables growth of stress-free GaN

The properties of group III-Nitrides (III-N) such as a large direct bandgap, high melting point, and high breakdown voltage make them very attractive for optoelectronic applications. However, conventional epitaxy on SiC and sapphire substrates results in strained and defective films with consequently poor device performance. In this work, by studying the nucleation of GaN on graphene/SiC by MOVPE, we unambiguously demonstrate the possibility of remote van der Waals epitaxy. By choosing the appropriate growth conditions, GaN crystals can grow either in-plane misoriented or fully epitaxial to the substrate. The adhesion forces across the GaN and graphene interface are very weak and the micron-scale nuclei can be easily moved around. The combined use of x-ray diffraction and transmission electron microscopy demonstrate the growth of stress-free and dislocation-free crystals. The high quality of the crystals was further confirmed by photoluminescence measurements. First principles calculations additionally highlighted the importance of the polarity of the underlying substrate. This work lays the first brick towards the synthesis of high quality III-N thin films grown via van der Waals epitaxy.

Al5+αSi5+δN12, a new Nitride compound

The family of III-Nitride semiconductors has been under intensive research for almost 30 years and has revolutionized lighting applications at the dawn of the 21st century. However, besides the developments and applications achieved, nitride alloys continue to fuel the quest for novel materials and applications. We report on the synthesis of a new nitride-based compound by using annealing of AlN heteroepitaxial layers under a Si-atmosphere at temperatures between 1350 °C and 1550 °C. The structure and stoichiometry of this compound are investigated by high resolution transmission electron microscopy (TEM) techniques and energy dispersive X-Ray (EDX) spectroscopy. Results are supported by density functional theory (DFT) calculations. The identified structure is a derivative of the parent wurtzite AlN crystal where the anion sublattice is fully occupied by N atoms and the cation sublattice is the stacking of 2 different planes along <0001>: The first one exhibits a ×3 periodicity along <11–20> with 1/3 of the sites being vacant. The rest of the sites in the cation sublattice are occupied by an equal number of Si and Al atoms. Assuming a semiconducting alloy, a range of stoichiometries is proposed, Al_5+αSi_5+δN₁₂ with α being between −2/3 and 1/4 and δ between 0 and 3/4.

[Opioid-induced adrenal insufficiency: Case report and synthesis of the literature]

INTRODUCTION

Opioid therapy for pain relief is associated with several adverse effects. Herein, we report the potential consequences of opioid use on the adrenal function.

OBSERVATION

A 49-year-old woman with sickle cell anemia (Hemoglobin SS) was admitted for the treatment of a vaso-occlusive crisis. Morphine was used for pain management, provided by intravenous intermittent dosing (patient-controlled analgesia). She developed during the hospitalization low blood pressure, due to secondary adrenal insufficiency (cortisol 74 nmol/L; ACTH 2.9pmol/L). Pituitary gland was normal on brain magnetic resonance imaging and adrenal function recovered after morphine discontinuation.

CONCLUSION

Opioids suppress cortisol secretion, primarily mediated by direct negative effect on hypothalamus and pituitary gland. Further studies are needed to define the incidence and the clinical significance of opioid-induced adrenal insufficiency, as well as the need for hormone replacement.

Silicene Nanostructures Grown on Graphene Covered SiC (0001) Substrate

Large nanostructures of silicene have been successfully grown on graphene covered 6H-SiC (0001) substrates. The graphene plays an important role to obtain honeycomb structures of silicon in the sp2 configuration and acts as an ideal template for 2D materials. The scanning tunneling microscopy images showed nanosheets of silicene with a very small buckling among the Si atoms. Our scanning tunneling spectroscopy confirmed the metallic character of the deposited silicene in excellent agreement with band structure calculations that also exhibit the presence of Dirac cones.

Extreme hypomagnesemia: characteristics of 119 consecutive inpatients

Extreme hypomagnesemia (hypoMg) can be encountered in many situations, but little data currently exist. Our aim is to describe the epidemiological, clinical, etiological characteristics, and the biological abnormalities of consecutive inpatients with extreme hypomagnesemia. In our observational monocentric study, between 1st July 2000 and April 2015, all inpatients with extreme hypomagnesemia, defined by at least one plasma magnesium concentration (P_Mg) below 0.3 mmol/L, were included. Demographic, clinical, biological characteristics and the drugs prescribed before the qualifying P_Mg measurement were retrospectively collected. 41,069 patients had at least one P_Mg assessment. The prevalence of extreme hypomagnesemia is 0.3% (119 inpatients). The median age is 70 years, 52% are women. The patients were mainly hospitalized in intensive care (n = 37, 31.1%), oncology (n = 21, 17.6%), gastroenterology (n = 18, 15.1%) and internal medicine (n = 16, 13.4%) departments. One hundred patients (84%) had a medical history of gastrointestinal disease (39% with bowel resections, 24% with stoma), and 50 (42%) had a cancer history. The drugs most commonly prescribed (known to induce hypoMg) are proton pump inhibitors (PPI) (n = 77, 70%), immunosuppressive regimens (n = 25, 22.5%), platinum salt-based chemotherapies (n = 19, 17.1%), and diuretics (n = 22, 19.8%). The suspected causes of hypomagnesemia are often multiple, but drugs (46%, including PPI in 19%) and chronic gastrointestinal disorders (37%) are prominent. Associated electrolyte disturbances include hypocalcemia (77%) and mild hypokalemia (51%). The 1-month mortality from all causes is 16%. Extreme hypomagnesemia is rare in inpatients, and is frequently associated with severe hypocalcemia. Digestive disorders and drugs are the main contributory causes.

[Use of pocket-sized ultrasound in internal medicine (hospitalist) practice: Feedback and perspectives]

INTRODUCTION

Point of care ultrasound (POCUS) is routinely used by intensivists and emergency physicians for many years. Its interest is not arguable any more for these specialists, despite the large variety of diseases they care. Hospitalists and internists also should find some interest in POCUS, which convenience and wide range of indications responds well to the variety of their practice. However, it is still not widely used in internal medicine departments.

METHODS

We here report our experience of using a pocket-sized ultrasound device in a French internal medicine department. The device used was a Vscan Dual Probe, GE, whose two probes and presets allow for cardiac, abdominal, pulmonary, obstetric, vascular, pulmonary, and superficial soft tissue exploration. One physician of the ward received a course for POCUS that was initially dedicated for emergency physicians. This study reports on the results of the examinations made between January and September 2015. For each examination performed, clinical usefulness was assessed at the time of patient discharge, by two independent physicians who reviewed the clinical course and the results of conventional imaging and rated their evaluation on a Likert scale.

RESULTS

One hundred and four examinations were evaluated. The mean duration of the ultrasound examination was 9±5minutes. The POCUS conclusions were corrected by disease course or the results of conventional imaging in 10 (9.6%) cases. The presets of the device: heart, soft tissue, lung, abdomen and vascular were used respectively in 32, 30, 21, 12 and 5% of the examinations. The main indications of POCUS examination were for identification of pleural, pericardial or peritoneal effusion, and to assess the central venous pressure by inferior vena cava examination. Eighteen examinations were performed for puncture of effusion. The retrospectively evaluated clinical benefit was clearly demonstrated in 78% of cases. The agreement between the two blinded assessors was good (kappa coefficient at 0.82).

CONCLUSION

Pocket-sized ultrasound device could be used in internal medicine wards. However, its limited performance compared to more sophisticated echography limits the possible explorations and their reliability, which encourages caution and makes critical the question of the initial training of doctors and medical students.

[Benign metastasizing leiomyoma: An unusual cause of aggressive femoral bone tumor]

BACKGROUND

Benign metastasizing leiomyoma (BML) is a rare condition characterized by histologically benign "metastatic" smooth muscle tumors, which can affect women with history of uterine surgery. We report the case of a patient with bone metastases of BML.

CASE REPORT

A 78-year-old woman who had undergone uterine surgery six years before hospital admission, was diagnosed with large pulmonary and pleural metastases that necessitated surgical removal. Pathological examination allowed the diagnosis of BML with positive staining for estrogen and progesterone receptors. Three years later, a BML metastasis in the right femoral diaphysis was unexpectedly discovered and treated by osteosynthesis because of a high risk of fracture. Despite an aromatase-inhibitor treatment, new lungs lesions appeared in the next few months.

CONCLUSION

BML is a potential cause of aggressive, although histologically benign, bone tumor in women with a history of uterine surgery.

A comparative study of graphene growth on SiC by hydrogen-CVD or Si sublimation through thermodynamic simulations

Thermodynamic simulations of SiC hydrogen annealing illustrating the impossibility of graphene formation due to the high pressure of C–H gases.

Cessation of oral anticoagulants in antiphospholipid syndrome

Objective

To study the outcome of patients with antiphospholipid syndrome (APS) after oral anticoagulant treatment cessation.

Methods

We performed a retrospective study of patients with APS experiencing cessation of oral anticoagulant and enrolled in a French multicentre observational cohort between January 2014 and January 2016. The main outcome was the occurrence of recurrent thrombotic event after oral anticoagulation cessation.

Results

Forty four APS patients interrupted oral anticoagulation. The median age was 43 (27–56) years. The median duration of anticoagulation was 21 (9–118) months. Main causes of oral anticoagulant treatment cessation were switch from vitamin K antagonists to aspirin in 15 patients, prolonged disappearance of antiphospholipid antibodies in ten, bleeding complications in nine and a poor therapeutic adherence in six. Eleven (25%) patients developed a recurrent thrombotic event after oral anticoagulation cessation, including three catastrophic APS and one death due to lower limb ischemia. Antihypertensive treatment required at time of oral anticoagulants cessation seems to be an important factor associated with recurrent thrombosis after oral anticoagulant cessation (15.2% in patients with no relapse versus 45.5% in patients with recurrent thrombosis, p = 0.038). Oral anticoagulant treatment was re-started in 18 (40.9%) patients.

Conclusion

The risk of a new thrombotic event in APS patients who stopped their anticoagulation is high, even in those who showed a long lasting disappearance of antiphospholipid antibodies. Except for the presence of treated hypertension, this study did not find a particular clinical or biological phenotype for APS patients who relapsed after anticoagulation cessation. Any stopping of anticoagulant in such patients should be done with caution.

Quantum Hall resistance standard in graphene devices under relaxed experimental conditions

The quantum Hall effect provides a universal standard for electrical resistance that is theoretically based on only the Planck constant h and the electron charge e. Currently, this standard is implemented in GaAs/AlGaAs, but graphene's electronic properties have given hope for a more practical device. Here, we demonstrate that the experimental conditions necessary for the operation of devices made of high-quality graphene grown by chemical vapour deposition on silicon carbide can be extended and significantly relaxed compared with those for state-of-the-art GaAs/AlGaAs devices. In particular, the Hall resistance can be accurately quantized to within 1 × 10(-9) over a 10 T wide range of magnetic flux density, down to 3.5 T, at a temperature of up to 10 K or with a current of up to 0.5 mA. This experimental simplification highlights the great potential of graphene in the development of user-friendly and versatile quantum standards that are compatible with broader industrial uses beyond those in national metrology institutes. Furthermore, the measured agreement of the quantized Hall resistance in graphene and GaAs/AlGaAs, with an ultimate uncertainty of 8.2 × 10(-11), supports the universality of the quantum Hall effect. This also provides evidence of the relation of the quantized Hall resistance with h and e, which is crucial for the new Système International d'unités to be based on fixing such fundamental constants of nature.

Association of residual plasma viremia and intima-media thickness in antiretroviral-treated patients with controlled human immunodeficiency virus infection

Background

While residual plasma viremia is commonly observed in HIV-infected patients undergoing antiretroviral treatment (ART), little is known about its subclinical consequences.

Methods

This cross-sectional study included 47 male, never-smoking, non-diabetic patients with ≥4 years of ART and controlled HIV-replication (HIV-viral load, VL <20 copies/mL for ≥1 year). Residual HIV-VL was measured using an ultrasensitive assay (quantification limit: 1 copy/ml). Patients were categorized as having detectable (D; 1-20 copies/mL, n = 14) or undetectable (UD; <1 copies/mL, n = 33) HIV-VL. Linear regression was used to model the difference in total carotid intima-media thickness [c-IMT, measures averaged across common carotid artery (cca), bifurcation, and internal carotid artery] and cca-IMT alone across detection groups. Multivariable models were constructed for each endpoint in a forward-stepwise approach.

Results

No significant differences were observed between viremia groups with respect to median ART-duration (9.6 years, IQR = 6.8–10.9), nadir CD4+T-cell (208/mm³, IQR = 143–378), and CD4+T-cell count (555/mm³, IQR = 458–707). Median adjusted inflammatory markers tended to be higher in patients with D- than UD-viremia, with differences in IL-10 being significant (p = 0.03). After adjustment on age, systolic blood pressure, and insulin resistance, mean cca-IMT was significantly lower in patients with undetectable (0.668 mm±0.010) versus detectable viremia (0.727 mm±0.015, p = 0.002). Cca-IMT was also independently associated with age and insulin resistance. Mean adjusted total c-IMT was no different between viremia groups (p = 0.2), however there was large variability in bifurcation c-IMT measurements.

Conclusions

Higher cca-IMT was observed in patients with detectable, compared to undetectable, HIV-VL in never-smoking ART-controlled patients, suggesting that residual HIV viremia may be linked to atherosclerosis.

Investigation of structural and electronic properties of epitaxial graphene on 3C-SiC(100)/Si(100) substrates

Graphene has been intensively studied in recent years in order to take advantage of its unique properties. Its synthesis on SiC substrates by solid-state graphitization appears a suitable option for graphene-based electronics. However, before developing devices based on epitaxial graphene, it is desirable to understand and finely control the synthesis of material with the most promising properties. To achieve these prerequisites, many studies are being conducted on various SiC substrates. Here, we review 3C-SiC(100) epilayers grown by chemical vapor deposition on Si(100) substrates for producing graphene by solid state graphitization under ultrahigh-vacuum conditions. Based on various characterization techniques, the structural and electrical properties of epitaxial graphene layer grown on 3C-SiC(100)/Si(100) are discussed. We establish that epitaxial graphene presents properties similar to those obtained using hexagonal SiC substrates, with the advantage of being compatible with current Si-processing technology.

High frequency of potentially pathogenic SORL1 mutations in autosomal dominant early-onset Alzheimer disease

Performing exome sequencing in 14 autosomal dominant early-onset Alzheimer disease (ADEOAD) index cases without mutation on known genes (amyloid precursor protein (APP), presenilin1 (PSEN1) and presenilin2 (PSEN2)), we found that in five patients, the SORL1 gene harbored unknown nonsense (n=1) or missense (n=4) mutations. These mutations were not retrieved in 1500 controls of same ethnic origin. In a replication sample, including 15 ADEOAD cases, 2 unknown non-synonymous mutations (1 missense, 1 nonsense) were retrieved, thus yielding to a total of 7/29 unknown mutations in the combined sample. Using in silico predictions, we conclude that these seven private mutations are likely to have a pathogenic effect. SORL1 encodes the Sortilin-related receptor LR11/SorLA, a protein involved in the control of amyloid beta peptide production. Our results suggest that besides the involvement of the APP and PSEN genes, further genetic heterogeneity, involving another gene of the same pathway is present in ADEOAD.

Plasmidic qnrA3 enhances Escherichia coli fitness in absence of antibiotic exposure

The widespread presence of plasmid-mediated quinolone resistance determinants, particularly qnr genes, has become a current issue. By protecting DNA-gyrase from quinolones, Qnr proteins confer a low level quinolone resistance that is not sufficient to explain their emergence. Since Qnr proteins were hypothesized to act as DNA-binding protein regulators, qnr genes could have emerged by providing a selective advantage other than antibiotic resistance. We investigated host fitness of Escherichia coli isogenic strains after acquisition of the qnrA3 gene, inserted either alone onto a small plasmid (pBR322), or harbored on a large conjugative native plasmid, pHe96(qnrA3) found in a clinical isolate. The isogenic strains were derived from the susceptible E. coli CFT073, a virulent B2 group strain known to infect bladder and kidneys in a mouse model of pyelonephritis. In vitro experiments included growth analysis by automatic spectrophotometry and flow cytometry, and competitions with CFU enumeration. In vivo experiments included infection with each strain and pairwise competitions in absence of antimicrobial exposure. As controls for our experiments we used mutations known to reduce fitness (rpsL K42N mutation) or to enhance fitness (tetA deletion in pBR322). E. coli CFT073 transformed with pBRAM(PBR322-qnrA3) had significantly higher maximal OD than E. coli CFT073 transformed with pBR322 or pBR322ΔtetA, and in vivo competitions were more often won by the qnrA3 carrying strain (24 victories vs. 9 loss among 42 competitions, p = 0.001). In contrast, when pHe96(qnrA3) was introduced by conjugation in E. coli CFT073, it exerted a fitness cost shown by an impaired growth observed in vitro and in vivo and a majority of lost competitions (33/35, p<0.0001). In conclusion, qnrA3 acquisition enhanced bacterial fitness, which may explain qnr emergence and suggests a regulation role of qnr. However, fitness was reduced when qnrA3 was inserted onto multidrug-resistant plasmids and this can slow down its dissemination without antibiotic exposure.

[Psychosocial assessment scale for demented in patients]

A crisis is an episode of desorganisation of the individual balance for the patient and his circle, but it is also an occasion for adaptation to the new systemic context created by the disease. The subjective assessment of clinical improvement made by the patient and staff should be completed by objective measures of the clinical evolution that reflects the efficiency of the care programs. This article describes the development of a french version of the Health of Nation Outcome Scale 65+F (HoNOS65+F) and shows that it can be used for the initial assessment in the context of crisis units. In addition, a recent study performed in our division demonstrated the sensitivity and specificity of this instrument for the assessent of changes in depressive symptoms in demented.

Working memory load-related electroencephalographic parameters can differentiate progressive from stable mild cognitive impairment

Recent studies described several changes of endogenous event-related potentials (ERP) and brain rhythm synchronization during memory activation in patients with Alzheimer's disease (AD). To examine whether memory-related EEG parameters may predict cognitive decline in mild cognitive impairment (MCI), we assessed P200 and N200 latencies as well as beta event-related synchronization (ERS) in 16 elderly controls (EC), 29 MCI cases and 10 patients with AD during the successful performance of a pure attentional detection task as compared with a highly working memory demanding two-back task. At 1 year follow-up, 16 MCI patients showed progressive cognitive decline (PMCI) and 13 remained stable (SMCI). Both P200 and N200 latencies in the two-back task were longer in PMCI and AD cases compared with EC and SMCI cases. During the interval 1000 ms to 1700 ms after stimulus, beta ERS at parietal electrodes was of lower amplitude in PMCI and AD compared with EC and SMCI cases. Univariate models showed that P200, N200 and log% beta values were significantly related to the SMCI/PMCI distinction with areas under the receiver operating characteristic curve of 0.93, 0.78 and 0.72, respectively. The combination of all three EEG hallmarks was the stronger predictor of MCI deterioration with 90% of correctly classified MCI cases. Our data reveal that PMCI and clinically overt AD share the same pattern of working memory-related EEG activation characterized by increased P200-N200 latencies and decreased beta ERS. They also show that P200 latency during the two-back task may be a simple and promising EEG marker of rapid cognitive decline in MCI.