In this work, the effect of heat treatment on the minority carrier lifetime (τ) in boron-doped crystalline silicon wafers coated with a silicon nitride (SiNx:H) layer has been investigated. The ...results showed an initial increase in τ during the early phase of light exposure of the samples, which was attributed to the presence of iron–boron complexes in the c-Si wafers. However, this enhancement was followed by a decrease associated with the formation of boron-oxygen complexes, known as light-induced degradation. Moreover, kinetic models were used to analyze defect interactions in the wafers, showing a correlation between τ behavior and hydrogen-boron complex concentrations, and related by analytical techniques. In addition, the samples were subjected to a dark annealing step, resulting in further degradation due to the firing temperature process and the presence of hydrogen atoms in the silicon nitride layer. Finally, this study provides valuable insights into defect formation mechanisms in c-Si wafers that could improve the stability and efficiency optimization of silicon-based solar cells under operating conditions.
Urchin-like NiCo
2
O
4
was synthesized onto flexible carbon felt (CF) substrate via facile hydrothermal process as a high performed electrode for supercapacitors. The hydrothermal temperature was ...varied from 140 to 200 °C in order to investigate its effect on the morphological, structural, and electrochemical properties of the as-synthesized NiCo
2
O
4
@CF. Moreover, X-ray diffraction analysis revealed the formation of NiCo
2
O
4
composite with polycrystalline nature. The SEM images demonstrate the development of NiCo
2
O
4
structure from nanowires to a combination between nanowires and urchin like during the increasing of the hydrothermal temperature. This combination is extremely advantageous in accomplishing an exceptional electrochemical capacity by virtue of the high surface area of interaction with electrolyte and the decrease in the ion transport path. Indeed, the double nanostructured NiCo
2
O
4
synthesized at 200 °C allowed to obtain excellent electrochemical performance with high specific capacity of 243.1 mAh.g
−1
(0.278 mAh.cm
−2
) at current value of 2 mA and capacity retention of ~ 91.3% after 5000 cycles in 6-M KOH aqueous electrolyte. As a consequence, the obtained double nanostructured NiCo
2
O
4
@CF flexible electrode is well suited for use in hybrid devices and flexible electronic devices.
Graphical Abstract
Antimicrobial-resistant
isolates have emerged in various ecologic compartments and evolved to spread globally. We sought to (1.) investigate the occurrence of ESBL-producing
(ESBL-Ec) in feces from ...free-range chickens in a rural region and (2.) characterize the genetic background of antimicrobial resistance and the genetic relatedness of collected isolates. Ninety-five feces swabs from free-range chickens associated with two households (House 1/House 2) in a rural region in northern Tunisia were collected. Samples were screened to recover ESBL-Ec, and collected isolates were characterized for phenotype/genotype of antimicrobial resistance, integrons, and molecular typing (pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST)). Overall, 47 ESBL-Ec were identified, with the following genes detected: 35
5
, 5
, 1
and 1
. Resistance to fluoroquinolones, tetracycline, sulfonamides, and colistin was encoded by
-Ib-
(
= 21),
B (
= 1), and
S (
= 2);
A (
= 17)/
B (
= 26);
1 (
= 29)/
2 (
= 18); and
-2 (
= 2) genes, respectively. PFGE and MLST identified genetic homogeneity of isolates in House 1; however, isolates from House 2 were heterogeneous. Notably, among nine identified sequence types, ST58, ST69, ST224, and ST410 belong to pandemic high-risk clonal lineages associated with extrapathogenic
. Minor clones belonging to ST410 and ST471 were shared by chickens from both households. The virulence genes
and
were detected in 35, 47, 17, and 23 isolates, respectively. Findings indicate a high occurrence of ESBL-Ec in free-range chickens and highlight the occurrence of pandemic zoonotic clones.
Introduction
Tuberculous Spondylodiscitis is the most common form of musculoskeletal tuberculosis. Molecular techniques on fresh tissues are proved to improve the diagnosis of tuberculous ...spondylodiscitis and to allow a rapid diagnosis to initiate the treatment and prevent neurological complications.
Objectives
The objective of the present study was to assess the diagnostic performances of single tube nested PCR and GeneXpert ultra in the diagnosis of tuberculous spondylodiscitis on formalin fixed paraffin embedded tissues.
Methods
This study included 63 tuberculous spondylodiscitis cases collected from June 2014 to January 2020 and corresponding to 27 definite tuberculous spondylodiscitis with positive microbiology, and 36 probable tuberculous spondylodiscitis, with histopathological, clinical and radiological findings consistent with tuberculous spondylodiscitis but with negative microbiology. The sensitivity, specificity, positive predictive value and negative predictive value of nested PCR and GeneXpert ultra were determined with reference to microbiology.
Results
Nested PCR was positive in 47 (75%) cases: 26/27 definite tuberculous spondylodiscitis and 21/36 probable tuberculous spondylodiscitis. GeneXpert ultra was positive in only 6 (10%) cases corresponding to definite tuberculous spondylodiscitis. The sensitivity, specificity, positive predictive value and negative predictive value of nested PCR on formalin fixed paraffin embedded tissues were 96%, 100%, 100%, 83% respectively. For GeneXpert ultra, these rates were 22%, 100%, 100% and 25% respectively.
Conclusion
Nested PCR and GeneXpert ultra on formalin fixed paraffin embedded tissues are useful tools for the diagnosis of tuberculous spondylodiscitis, especially for cases where microbiological investigations were not carried out. Both techniques have excellent specificity but single tube nested PCR is more sensitive.
Key Points
•
Molecular techniques are routinely performed on fresh tissues
•
GeneXpert and nested PCR on formalin fixed paraffin embedded tissues are reliable for the diagnosis of tuberculous spondylodiscitis
•
Nested PCR is more sensitive than Genexpert for diagnosing tuberculous spondylodiscitis
Background
We investigated the diversity of the primary sequences of the 16S rRNA genes among 46 commensal Neisseria strains and evaluated the use of this approach as a molecular typing tool in ...comparison with PFGE analysis.
Methods
Identification to the genus was done using conventional methods and API NH (bio‐Mérieux®). Identification to species level was based on 16S rRNA gene sequencing. PFGE analysis was done using SpeI.
Results
Fourteen, two, three and fourteen 16S rRNA sequence types were found among twenty Neisseria flavescens, two Neisseria sicca, five Neisseria macacae and nineteen Neisseria mucosa clinical isolates. Forty‐three different PFGE patterns were found among the tested strains.
Conclusion
We demonstrated a high diversity among 16S rRNA genes which was reflected by PFGE analysis.
Pedagogical workshop planning is challenging especially when we aim to promote a reflective practice of the tutees. This practice has been widely discussed in the literature without a real consensus. ...Some authors reported oral exercises or anecdotes, other described writings or even storytelling. The aim of the authors was to describe the different steps performed by the tutors and to assess the tutees’ satisfaction.
This was a pilot study dealing with the use of the prospective strategy principles in order to plan a pedagogical workshop. Included participants were early academic teacher trainees.
The authors illustrated how they planned a pedagogical workshop using the prospective strategy and highlighted the satisfaction of the tutees.
Prospective strategy is mainly used in economic field in order to change the future of the companies by acting on different intervening factors. Associating prospective strategy to pedagogical principles hasn’t been reported in the medical literature and seems to be available in order to induce reflective practice.
La planificación del taller pedagógico es un desafío, especialmente cuando nuestro objetivo es promover una práctica reflexiva de los alumnos. Esta práctica ha sido ampliamente discutida en la literatura sin un consenso real. Algunos autores informaron ejercicios orales o anécdotas, otros escritos descritos o incluso narraciones. El objetivo de los autores fue describir los diferentes pasos realizados por los tutores y evaluar la satisfacción de los alumnos.
Este fue un estudio piloto que trató sobre el uso de los principios de la estrategia prospectiva para planificar un taller pedagógico. Los participantes incluidos fueron los primeros aprendices de docentes académicos.
Los autores ilustraron cómo planearon un taller pedagógico utilizando la estrategia prospectiva y destacaron la satisfacción de los alumnos.
La estrategia prospectiva se utiliza principalmente en el campo económico para cambiar el futuro de las empresas actuando sobre diferentes factores intermedios. Asociar la estrategia prospectiva a los principios pedagógicos no se ha informado en la literatura médica y parece estar disponible para inducir la práctica reflexiva.
Pneumococcal disease, a major cause of morbidity and mortality globally, has higher incidence among young children, the elderly and the immunocompromised of all ages. In Tunisia, pneumococcal ...conjugate vaccines (PCVs) are not included in the national immunization program. Also, few studies have described the epidemiology of S. pneumoniae in this country and, in particular, no molecular typing studies have been performed. The aim of this study was to evaluate serotype distribution, antimicrobial resistance and clonality of Streptococcus pneumoniae isolated from neutropenic patients in Tunisia.
Fifty-nine S. pneumoniae were isolated from infection (n = 31) and colonization (n = 28) sites of patients (children and adults) attending the National Centre of Bone Marrow Transplantation in Tunis between 2005-2011. All isolates were characterized by serotype, antimicrobial resistance pattern and multilocus sequence typing (MLST).
The majority (66.1%) of the isolates belonged to five serotypes all included in PCVs: 6B, 9V, 14, 19F and 23F. The potential coverage of the 10-valent and 13-valent PCV was of 71.2% and 76.3% respectively. Resistance rates were very high and 69.5% of the isolates were multidrug resistant: non-susceptibility rates to penicillin, amoxicillin and cefotaxime were 66.1%, 40.7% and 27.1%, respectively; resistance rates to erythromycin, clindamycin, tetracycline, chloramphenicol and trimethoprim-sulfamethoxazole, were 69.5%, 61.0%, 37.3%, 22.0% and 67.8%, respectively. The most frequent serotypes had STs characteristic of multidrug resistant international clones known to be highly successful and important causes of pneumococcal infection: Spain 23F-ST81, France 9V/14-ST156, Spain 6B-ST90, 19F-ST320, and Portugal 19F-ST177.
The majority of S. pneumoniae strains recovered from immunocompromised patients in Tunisia are representatives of multidrug resistant pandemic clones that express serotypes targeted by PCVs. To contain the burden of pneumococcal disease and improve treatment choices among Tunisian immunocompromised patients PCVs should be offered to all of them.
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