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.
AlN thin films, grown on (0001) sapphire substrates by molecular beam epitaxy (MBE), were annealed at high temperature (up to 1650°C) in flowing N2. X-ray diffraction (XRD) studies, combined with ...Williamson-Hall and Srikant plots, have shown that annealing leads to a strong reduction of both edge and mixed threading dislocation densities, as confirmed by transmission electron microscopy (TEM) images, up to 75%. Moreover, it is found that annealing at high temperatures allows the relaxation of the tensile strain in the AlN film due to the growth process. In addition, the morphological properties of the films were determined by atomic force microscopy (AFM) and show that the annealing conditions have a strong impact on the surface morphology and roughness. Finally, an annealing at 1550°C for 20min appears as an ideal tradeoff to enhance the structural properties while preserving the initial AlN surface morphology.
•Annealing and structural characterization of AlN epitaxial layers on sapphire.•Strong reduction of both edge and mixed threading dislocation densities.•Strong impact of the annealing conditions on the surface morphology.•Effect of the annealing on the in-plane lattice parameter of the AlN layers.
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 RFormula: see text greater than 0.9 and mean absolute errors (MAE) smaller than 0.23 eV both for the training and prediction. The highest RFormula: 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.
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.
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.
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.
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.
Neurological complications of varicella zoster virus reactivation can involve the central and peripheral nervous systems. Central nervous system involvement was associated with a higher mortality and peripheral involvement with higher sequelae. Higher age and Rankin scale prior to infection were associated with a poorer prognosis.
The electronic properties of the graphene (Gr) Schottky junction with an Al0.22Ga0.78N/GaN heterostructure on silicon have been investigated, both by experiment and with use of ab initio DFT ...calculations. A peculiarly high n-type doping (1.1 × 1013 cm–2), observed for Gr in contact with AlGaN, was explained by the combined effect of Fermi level pinning by AlGaN surface states and charge transfer. Spatially uniform current injection across the Gr/AlGaN/GaN heterojunction was revealed by nanoscale resolution conductive atomic force microscopy (CAFM) analyses. Furthermore, a Gr/AlGaN/GaN Schottky diode with excellent rectifying behavior has been demonstrated and used as the key building block for a hot electron transistor (HET) with a 10 nm Al2O3 base-collector barrier. Thanks to the highly efficient hot electron injection from the AlGaN/GaN emitter, this transistor exhibits high on-state current density (J C,ON ≈ 1 A/cm2), high on-state over off-state current density ratio (J C,ON/J C,OFF ≈ 106), and a common-base current gain α ≈ 0.15, solely limited by the high Al2O3 base–collector barrier. The excellent performances of the Gr/AlGaN/GaN Schottky junction represent an important step toward the development of a HET technology compatible with the state-of-the-art GaN high electron mobility transistors.
(111)-oriented cubic polytypes of silicon carbide (3C-SiC) films were grown by chemical vapor deposition on 2H-AlN(0001)/Si(111) and 2H-AlN(0001)/Si(110) templates. The structural and electrical ...properties of the films were investigated. For film thicknesses below 300 nm, the 3C-SiC material deposited on 2H-AlN/Si presented a better structural quality than the 3C-SiC films grown directly on Si(111) using the well-established two-step carbonization–epitaxy process. The good lattice match of 3C-SiC with AlN may open a reliable route towards high-quality thin heteroepitaxial 3C-SiC films on a silicon wafer. Nevertheless, the 3C-SiC was featured by the presence of twinned domains and small inclusions of 6H-SiC. The formation of a thin AlSiN film at the AlN/Si interface is also reported. This is the first time such AlSiN layers are described within an AlN/Si heterostructure. Furthermore, noticeable modifications were observed in the AlN film. First, the growth process of SiC on AlN induced a reduction of the dislocation density in the AlN, attesting to the structural healing of AlN with thermal treatment, as already observed for other AlN-based heterostructures with higher-temperature processes. The growth of SiC on AlN also induced a dramatic reduction in the insulating character of the AlN, which could be related to a noticeable cross-doping between the materials.
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.
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