Resonant Raman spectroscopy is a powerful tool for providing information about excitons and exciton–phonon coupling in two-dimensional materials. We present here resonant Raman experiments of ...single-layered WS2 and WSe2 using more than 25 laser lines. The Raman excitation profiles of both materials show unexpected differences. All Raman features of WS2 monolayers are enhanced by the first-optical excitations (with an asymmetric response for the spin–orbit related XA and XB excitons), whereas Raman bands of WSe2 are not enhanced at XA/B energies. Such an intriguing phenomenon is addressed by DFT calculations and by solving the Bethe-Salpeter equation. These two materials are very similar. They prefer the same crystal arrangement, and their electronic structure is akin, with comparable spin–orbit coupling. However, we reveal that WS2 and WSe2 exhibit quite different exciton–phonon interactions. In this sense, we demonstrate that the interaction between XC and XA excitons with phonons explains the different Raman responses of WS2 and WSe2, and the absence of Raman enhancement for the WSe2 modes at XA/B energies. These results reveal unusual exciton–phonon interactions and open new avenues for understanding the two-dimensional materials physics, where weak interactions play a key role coupling different degrees of freedom (spin, optic, and electronic).
La prise en charge des infections urinaires (IU) de l’enfant est à un tournant tant en ce qui concerne les méthodes diagnostiques à utiliser, la nécessité de dépister un reflux vésico-urétéral, ...l’intérêt de l’antibioprophylaxie et l’émergence de souches d’E. coli multi résistantes. Le Groupe de Pathologie Infectieuse Pédiatrique de la Société Française de Pédiatrie prend position pour : (i) un recours plus fréquent aux bandelettes urinaires et, pour l’ECBU, à d’autres modes de prélèvement que la poche à urines (prélèvement au jet, cathétérisme urétral, ponction sus pubienne) ; (ii) ne pas bouleverser les propositions thérapeutiques initiales de l’Ex-AFSSAPS (même si le pourcentage de souches de E. coli BLSE avoisine les 10 %) mais dès maintenant, récupérer le plus rapidement possible le résultat des antibiogrammes (afin de mettre en place au plus tôt un traitement antibiotique efficace contre une souche résistante) et d’augmenter la proportion d’enfants recevant d’emblée un traitement par aminosides (qui reste actif sur la majorité des souches BLSE) en monothérapie ; (iii) de réduire la prescription de cystographie rétrograde et des antibioprophylaxies, sauf circonstances particulières (récidives, anomalies majeures à l’échographie).
Management of urinary tract infections (UTI) in children is at a crossroads both in regard to the diagnostic methods used, the need to detect vesico-ureteral reflux, the benefit of prophylactic antibiotics and the emergence strains of multiresistant E. coli. The Groupe de Pathologie Infectieuse Pédiatrique of French Society of Pediatrics takes position : (i) to utilize more frequently urinary dipsticks and for urinary cultures, other methods of urine sampling than bag (sample jet, urethral catheterization, supra-pubic puncture) ; (ii) do not alter the initial therapeutic proposals of the former AFSSAPS (despite the percentage of E. coli ESBL around 10 %), but now, as soon as possible to recover the result of susceptibility testing to quickly change (for effective antibiotic treatment against a resistant strain) and to increase the proportion of children receiving initial treatment with aminoglycosides monotherapy (which remains active on the majority of ESBL strains) ; (iii) to reduce the prescription of antibiotic prophylaxis and retrograde cystography, except in special circumstances (recurrence, major abnormalities on ultrasound).
Background. Necrotizing pneumonia due to Panton-Valentine leukocidin–producing strains of Staphylococcus aureus is associated with a high mortality rate. We sought factors associated with vital ...outcome in 50 cases occurring from 1986 through 2005. Methods. We compared the clinical and biological characteristics of 50 patients according to their vital outcome and examined the characteristics of the corresponding S. aureus isolates. Results. The overall mortality rate was 56%, and the median survival time was 10 days. All of the deaths were attributed to S. aureus infection and were secondary to refractory shock and/or respiratory failure. Fatal outcome was associated with classical severity factors, such as the need for mechanical ventilation or inotrope support, and with onset of the acute respiratory distress syndrome. Airway bleeding was strongly associated with fatal outcome (P = .002). Patients who had focal staphylococcal infection before the onset of pneumonia had a significantly lower mortality rate (P = .002). The main biological feature associated with death was leukopenia (P <t; .001). In multivariate analysis, leukopenia and erythroderma occurring within the first 24 h after admission to the hospital were independently associated with fatal outcome. Erythroderma was not associated with toxic shock syndrome toxin. Conclusions. Airway bleeding, erythroderma, and leukopenia are associated with fatal outcome from Panton-Valentine leukocidin–positive S. aureus necrotizing pneumonia. More work is needed to develop more efficacious therapy against this highly lethal disease.
ABINIT is a package whose main program allows one to find the total energy, charge density, electronic structure and many other properties of systems made of electrons and nuclei, (molecules and ...periodic solids) within Density Functional Theory (DFT), Many-Body Perturbation Theory (GW approximation and Bethe–Salpeter equation) and Dynamical Mean Field Theory (DMFT). ABINIT also allows to optimize the geometry according to the DFT forces and stresses, to perform molecular dynamics simulations using these forces, and to generate dynamical matrices, Born effective charges and dielectric tensors. The present paper aims to describe the new capabilities of ABINIT that have been developed since 2009. It covers both physical and technical developments inside the ABINIT code, as well as developments provided within the ABINIT package. The developments are described with relevant references, input variables, tests and tutorials.
Program title: ABINIT
Catalogue identifier: AEEU_v2_0
Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEU_v2_0.html
Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland
Licensing provisions: GNU General Public License, version 3
No. of lines in distributed program, including test data, etc.: 4845789
No. of bytes in distributed program, including test data, etc.: 71340403
Distribution format: tar.gz
Programming language: Fortran2003, PERL scripts, Python scripts.
Classification: 7.3, 7.8.
External routines: (all optional) BigDFT 2, ETSF_IO 3, libxc 4, NetCDF 5, MPI 6, Wannier90 7, FFTW 8.
Catalogue identifier of previous version: AEEU_v1_0
Journal reference of previous version: Comput. Phys. Comm. 180 (2009) 2582
Does the new version supersede the previous version?: Yes. The abinit-7.10.5 version is now the up to date stable version of ABINIT
Nature of problem:
This package has the purpose of computing accurately material and nanostructure properties: electronic structure, bond lengths, bond angles, primitive cell size, cohesive energy, dielectric properties, vibrational properties, elastic properties, optical properties, magnetic properties, non-linear couplings, electronic and vibrational life-times, and others.
Solution method:
Software application based on Density Functional Theory, Many-Body Perturbation Theory and Dynamical Mean Field Theory, pseudopotentials, with plane waves or wavelets as basis functions.
Reasons for new version:
Since 2009, the abinit-5.7.4 version of the code has considerably evolved and is not yet up to date. The abinit- 7.10.5 version contains new physical and technical features that allow electronic structure calculations impossible to carry out in the previous versions.
Summary of revisions:•new physical features: quantum effects for the nuclei treated by the Path-integral Molecular Dynamics; finding transition states using image dynamics (NEB or string methods); two component DFT for electron-positron annihilation; linear response in a Projector Augmented-Wave approach -PAW-, electron-phonon interactions and temperature dependence of the gap; Bethe Salpeter Equation -BSE-; Dynamical Mean Field Theory (DMFT).•new technical features: development of a PAW approach for a wavelet basis; parallelisation of the code on more than 10,000 processors; new build system.•new features in the ABINIT package: tests; test farm; new tutorials; new pseudopotentials and PAW atomic data tables; GUI and postprocessing tools like the AbiPy and APPA libraries.Running time:
It is difficult to answer to the question as the use of ABINIT is very large. On one hand, ABINIT can run on 10,000 processors for hours to perform quantum molecular dynamics on large systems. On the other hand, tutorials for students can be performed on a laptop within a few minutes.
References:1http://www.gnu.org/copyleft/gpl.txt2http://bigdft.org3http://www.etsf.eu/fileformats4http://www.tddft.org/programs/octopus/wiki/index.php/Libxc5http://www.unidata.ucar.edu/software/netcdf6https://en.wikipedia.org/wiki/Message_Passing_Interface7http://www.wannier.org8M. Frigo and S.G. Johnson, Proceedings of the IEEE, 93, 216–231 (2005).
Background. Pneumococcal serotypes 1, 3, 5, 7F, and 19A were the most implicated in community-acquired pneumonia (CAP) after implementation of 7-valent pneumococcal conjugate vaccine (PCV7). In ...France, the switch from PCV7 to 13-valent pneumococcal conjugate vaccine (PCV13) occurred in June 2010. An active surveillance network was set up to analyze the impact of PCV13 on CAP. Methods. An observational prospective study performed in 8 pediatric emergency departments from June 2009 to May 2012 included all children between 1 month and 15 years of age with chest radiography–confirmed pneumonia. Three 1-year periods were defined: pre-PCV13, transitional, and post-PCV13. Results. During the 3-year study period, among the 953 274 pediatric emergency visits, 5645 children with CAP were included. CAP with pleural effusion and documented pneumococcal CAP were diagnosed in 365 and 136 patients, respectively. Despite an increase (4.5%) in number of pediatric emergency visits, cases of CAP decreased by 16% (2060 to 1725) between pre- and post-PCV13 periods. The decrease reached 32% in infants in the same periods (757 to 516; P < .001). Between pre- and post-PCV13 periods, the proportion of CAP patients with a C-reactive protein level >120 mg/dL decreased from 41.3% to 29.7% (P < .001), the number of pleural effusion cases decreased by 53% (167 to 79; P < .001) and the number of pneumococcal CAP cases decreased by 63% (64 to 24; P = .002). The number of additional PCV13 serotypes identified decreased by 74% (27 to 7). Conclusions. Our data suggest a strong impact of PCV13 on CAP, pleural effusion, and documented pneumococcal pneumonia, particularly cases due to PCV13 serotypes.
In recent years, metagenomic Next-Generation Sequencing (mNGS) has increasingly been used for an accurate assumption-free virological diagnosis. However, the systematic workflow evaluation on ...clinical respiratory samples and implementation of quality controls (QCs) is still lacking.
A total of 3 QCs were implemented and processed through the whole mNGS workflow: a no-template-control to evaluate contamination issues during the process; an internal and an external QC to check the integrity of the reagents, equipment, the presence of inhibitors, and to allow the validation of results for each sample. The workflow was then evaluated on 37 clinical respiratory samples from patients with acute respiratory infections previously tested for a broad panel of viruses using semi-quantitative real-time PCR assays (28 positive samples including 6 multiple viral infections; 9 negative samples). Selected specimens included nasopharyngeal swabs (n = 20), aspirates (n = 10), or sputums (n = 7).
The optimal spiking level of the internal QC was first determined in order to be sufficiently detected without overconsumption of sequencing reads. According to QC validation criteria, mNGS results were validated for 34/37 selected samples. For valid samples, viral genotypes were accurately determined for 36/36 viruses detected with PCR (viral genome coverage ranged from 0.6 to 100%, median = 67.7%). This mNGS workflow allowed the detection of DNA and RNA viruses up to a semi-quantitative PCR Ct value of 36. The six multiple viral infections involving 2 to 4 viruses were also fully characterized. A strong correlation between results of mNGS and real-time PCR was obtained for each type of viral genome (R
ranged from 0.72 for linear single-stranded (ss) RNA viruses to 0.98 for linear ssDNA viruses).
Although the potential of mNGS technology is very promising, further evaluation studies are urgently needed for its routine clinical use within a reasonable timeframe. The approach described herein is crucial to bring standardization and to ensure the quality of the generated sequences in clinical setting. We provide an easy-to-use single protocol successfully evaluated for the characterization of a broad and representative panel of DNA and RNA respiratory viruses in various types of clinical samples.
La vulvovaginite est l’affection gynécologique la plus fréquente chez la fille prépubère. Elle peut être due à une bactérie sexuellement transmissible : Neisseria gonorrhoeae. Dans ce cas, un abus ...sexuel est systématiquement évoqué. Nous rapportons le cas d’une fillette de 5ans chez qui un diagnostic de vulvovaginite à gonocoque avait été porté. L’examen clinique et l’interrogatoire de la fillette et de ses parents, réalisés par 2 pédiatres expérimentés, n’ont pas permis de mettre en évidence d’argument évocateur d’abus sexuel. Les 2 parents présentaient des signes évocateurs de gonococcie, une urétrite pour le père et une vaginite pour la mère. Après revue de la littérature, nous avons constaté que d’autres modes de transmission que la voie sexuelle étaient possibles : par voie manuportée et surtout par vecteur passif (linge de toilette, thermomètre rectal, …). Nous avons donc retenu une probable contamination accidentelle intrafamiliale pour notre jeune patiente. La connaissance de ces modes de transmission parait indispensable à l’évaluation, toujours difficile, de ces situations et à l’information le cas échéant des autorités judiciaires.
Vulvovaginitis is the most frequent gynecologic pathology among prepubertal females. An infectious cause is found in 30% of cases and is highly associated with the presence of vaginal discharge upon examination. Neisseria gonorrhoeae may be one of the causative agents. Since N. gonorrhoeae is a common sexually transmitted disease, sexual abuse should be considered in the pediatric setting. We report the case of a 5-year-old girl with N. gonorrhoeae vulvovaginitis. Her previous history, multiple interviews with the patient and her parents, and clinical examination showed no evidence or signs of sexual abuse. Both parents presented gonorrhea, urethritis for the father and vaginitis for the mother. The discrepancy between pediatric evaluation and the presence of a bacterium associated with sexually transmitted disease led us to consider other means of contamination. Previous studies have shown that other routes of transmission are possible but are often neglected. Hence, contamination can be transmitted by the hands or mostly through passive means (towels, rectal thermometer, etc.). Many epidemics have been noted in group settings with young girls with no evidence of sexual transmission. Therefore, we concluded that this patient's infection was likely an accidental transmission within her family. The acknowledgement of these transmission routes is very important in order to avoid misguided suspicion of sexual abuse and the possible traumatic family and psychosocial consequences.