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Purpose: We propose a comprehensive workflow to design and build fully customized dense receive arrays for MRI, providing prediction of SNR and g-factor. Combined with additive manufacturing, this method allows an efficient implementation for any arbitrary loop configuration. To demonstrate the methodology, an innovative two-layer, 32-channel receive array is proposed., Methods: The design workflow is based on numerical simulations using a commercial 3D electromagnetic software associated with circuit model co-simulations to provide the most accurate results in an efficient time. A model to compute the noise covariance matrix from circuit model scattering parameters is proposed. A 32-channel receive array at 7 T is simulated and fabricated with a two-layer design made of non-geometrically decoupled loops. Decoupling between loops is achieved using home-built direct high-impedance preamplifiers. The loops are 3D-printed with a new additive manufacturing technique to speed up integration while preserving the detailed geometry as simulated. The SNR and parallel-imaging performances of the proposed design are compared with a commercial coil, and in vivo images are acquired., Results: The comparison of SNR and g-factors showed a good agreement between simulations and measurements. Experimental values are comparable with the ones measured on the commercial coil. Preliminary in vivo images also ensured the absence of any unexpected artifacts., Conclusion: A new design and performance analysis workflow is proposed and tested with a non-conventional 32-channel prototype at 7 T. Additive manufacturing of dense arrays of loops for brain imaging at ultrahigh field is validated for clinical use., (© 2023 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)

Background: The MELODY system allows for performing ultrasonography on a patient remotely and has been proposed to assess disease characteristics in the context of the coronavirus disease 2019 (COVID-19) pandemic. The aim of this interventional crossover study was to address the feasibility of the system in children aged 1 to 10 years old., Methods: Children underwent ultrasonography with a telerobotic ultrasound system followed by a second conventional examination by a different sonographer., Results: In total, 38 children were enrolled, and 76 examinations were performed, with 76 scans analyzed. The mean [standard deviation (SD)] age of participants was 5.7 (2.7) years (range, 1-10 years). We found substantial agreement between telerobotic and conventional ultrasonography [κ=0.74 (95% CI: 0.53-0.94), P<0.005]. The mean (SD) duration was longer for telerobotic than conventional examinations [26.0 (2.5) vs. 13.9 (11.2) min, P<0.0001]. Abdominal organs and abnormalities were similarly visualized on telerobotic and conventional ultrasonography. Cardiac echocardiography provided reliable diagnoses, with non-significantly different measurements with both techniques, although the visualization score was significantly higher with conventional than telerobotic ultrasonography (P<0.05). On lung analysis, both examinations identified consolidations and pleural effusion, whereas visualization and total lung score were similar with the 2 techniques. Overall, 45% of parents reported that their children felt less pressure with the telerobotic system., Conclusions: Telerobotic ultrasonography may be effective, feasible, and well-tolerated in children., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tp.amegroups.com/article/view/10.21037/tp-22-569/coif). The authors have no conflicts of interest to declare., (2023 Translational Pediatrics. All rights reserved.)

Objective: To describe neurologic, radiologic and laboratory features in children with central nervous system (CNS) inflammatory disease complicating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection., Study Design: We focused on CNS inflammatory diseases in children referred from 12 hospitals in the Paris area to Necker-Sick Children Reference Centre., Results: We identified 19 children who had a history of SARS-CoV-2 infection and manifest a variety of CNS inflammatory diseases: encephalopathy, cerebellar ataxia, acute disseminated encephalomyelitis, neuromyelitis optica spectrum disorder, or optic neuritis. All patients had a history of SARS-CoV-2 exposure, and all tested positive for circulating antibodies against SARS-CoV-2. At the onset of the neurologic disease, SARS-CoV-2 PCR results (nasopharyngeal swabs) were positive in 8 children. Cerebrospinal fluid was abnormal in 58% (11/19) and magnetic resonance imaging was abnormal in 74% (14/19). We identified an autoantibody co-trigger in 4 children (myelin-oligodendrocyte and aquaporin 4 antibodies), representing 21% of the cases. No autoantibody was found in the 6 children whose CNS inflammation was accompanied by a multisystem inflammatory syndrome in children. Overall, 89% of patients (17/19) received anti-inflammatory treatment, primarily high-pulse methylprednisolone. All patients had a complete long-term recovery and, to date, no patient with autoantibodies presented with a relapse., Conclusions: SARS2-CoV-2 represents a new trigger of postinfectious CNS inflammatory diseases in children., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objectives: We need studies assessing therapeutic options for oral relay in febrile urinary tract infection (FUTI) due to ESBL-producing Enterobacteriaceae (ESBL-E) in children. Amoxicillin-clavulanate/cefixime (AC-cefixime) combination seems to be a suitable option. We sought to describe the risk of recurrence at 1 month after the end of treatment for FUTI due to ESBL-E according to the oral relay therapy used., Materials and Methods: We retrospectively identified children <18 years who were included in a previous prospective observational multicentric study on managing FUTI due to ESBL-E between 2014 and 2017 in France. We collected whether children who received cotrimoxazole, ciprofloxacin or the AC-cefixime combination as the oral relay therapy reported a recurrence within the first month after the end of treatment. Then, we analyzed the susceptibility drug-testing of the strains involved., Results: We included 199 children who received an oral relay therapy with cotrimoxazole (n = 72, 36.2%), ciprofloxacin (n = 38, 19.1%) or the AC-cefixime combination (n = 89, 44.7%). Nine (4.5%) patients had a recurrence within the first month after the end of treatment, with no difference between the 3 groups of oral relay (p = 0.8): 4 (5.6%) cotrimoxazole, 2 (5.3%) ciprofloxacin and 3 (3.4%) AC-cefixime combination. Phenotype characterization of 249 strains responsible for FUTI due to ESBL-E showed that 97.6% were susceptible to the AC-cefixime combination., Conclusions: The AC-cefixime combination represents an interesting therapeutic option for oral relay treatment of FUTI due to ESBL-E as the recurrence rate at 1 month after the end of treatment was the same when compared to cotrimoxazole and ciprofloxacin., Competing Interests: The authors have declared that no competing interests exist.

In this paper we address the possibility to perform imaging of two samples within the same acquisition time using coupled ceramic resonators and one transmit/receive channel. We theoretically and experimentally compare the operation of our ceramic dual-resonator probe with a wire-wound solenoid probe, which is the standard probe used in ultrahigh-field magnetic resonance microscopy. We show that due to the low-loss ceramics used to fabricate the resonators, and a favorable distribution of the electric field within the conducting sample, a dual probe, which contains two samples, achieves an SNR enhancement by a factor close to the square root of 2 compared with a solenoid optimized for one sample., (© 2020 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.)

Understanding the clinical presentation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and prognosis in children is a major issue. Children often present mild symptoms, and some severe forms require paediatric intensive care, with in some cases a fatal prognosis. Our aim was to identify the epidemiological characteristics, clinical presentation, and prognosis of children with coronavirus disease 2019 (Covid-19) hospitalized in Paris suburb hospitals. In this prospective, observational, multicentre study, we included children hospitalized in paediatric departments of Paris suburb hospitals from 23 March 2020 to 10 May 2020, during the national lockdown in France with confirmed SARS-CoV-2 infection (positive RNA test on a nasopharyngeal swab) or highly suspected infection (clinical, biological, and/or radiological data features suggestive for SARS-CoV-2 infection). A total of 192 children were included for confirmed ( n = 157) or highly suspected ( n = 35) SARS-CoV-2 infection. The median age was one year old (interquartile range 0.125-11) with a sex ratio 1.3:1. Fever was recorded in 147 (76.6%) children and considered poorly tolerated in 29 (15.1%). The symptoms ranged from rhinorrhoea (34.4%) and gastrointestinal (35.5%) to respiratory distress (25%). Only 10 (5.2%) children had anosmia and five (2.6%) had chest pain. An underlying condition was identified in almost 30% of the children in our study. Overall, 24 (12.5%) children were admitted to paediatric intensive care units, 12 required mechanical ventilation, and three died. For children in Paris suburbs, most cases of Covid-19 showed mild or moderate clinical expression. However, one-eighth of children were admitted to paediatric intensive care units and three died., Competing Interests: The authors have no potential conflicts of interest related to this article.

In this paper, we propose, design and test a new dual-nuclei RF-coil inspired by wire metamaterial structures. The coil operates as a result of resonant excitation of hybridized eigenmodes in multimode flat periodic structures comprising several coupled thin metal strips. It was shown that the field distribution of the coil (i.e. penetration depth) can be controlled independently at two different Larmor frequencies by selecting a proper eigenmode in each of two mutually orthogonal periodic structures. The proposed coil requires no lumped capacitors to be tuned and matched. In order to demonstrate the performance of the new design, an experimental preclinical coil for 19 F/ 1 H imaging of small animals at 7.05T was engineered and tested on a homogeneous liquid phantom and in-vivo. The results demonstrate that the coil was both well tuned and matched at two Larmor frequencies and allowed image acquisition at both nuclei. In an in-vivo experiment, it was shown that without retuning the setup it was subsequently possible to obtain anatomical 1 H images of a mouse under anesthesia with 19 F images of a tiny tube filled with a fluorine-containing liquid and attached to the body of the mouse.

Objectives: The aim was to describe the epidemiological characteristics of childhood IgA vasculitis (IgAV) defined by the EULAR/PRINTO/Paediatric Rheumatology European Society criteria in a population-based sample from France and ascertain its incidence over 3 years by a four-source capture-recapture analysis., Methods: Cases were prospectively collected in Val de Marne county, a suburb of Paris, with 263 874 residents <15 years old. Children with incident IgAV living in this area from 2012 to 2014 were identified by four sources of case notification (emergency departments, paediatrics departments, private-practice paediatricians and general practitioners). Annual incidence was calculated, and a capture-recapture analysis was used with log-linear modelling to estimate case-finding completeness., Results: We identified 147 incident cases [78 boys; mean age 6.5 (s.d.:2.6) years]. The annual incidence (95% CI) was 18.6 (13.6, 24.5)/100 000 children. Although only 10% of children were exclusively identified by non-hospital sources, the completeness of case finding was 62%, with an undercount-corrected annual incidence (95% CI) of 29.9 (23.7, 37.3)/100 000 children. The annual distribution of diagnoses consistently showed a trough in summer months; 72% of children had infectious symptoms (mainly upper respiratory tract) a few days before IgAV onset; and 23% had a North African background., Conclusion: Our study supports secular and geospatial stability in childhood IgAV incidence and adds further indirect evidence for a possible role of a ubiquitous, non-emerging infectious trigger. Incidence studies from understudied areas are needed to disentangle the role of genetic factors better. Capture-recapture analysis suggests that a substantial portion of IgAV cases may remain unrecognized in epidemiological surveys., (© The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com)

Parallel transmission is a very promising method to tackle B 1 + field inhomogeneities at ultrahigh field in magnetic resonant imaging (MRI). This technique is however limited by the mutual coupling between the radiating elements. Here we propose to solve this problem by designing a passive magneto-electric resonator that we here refer to as stacked magnetic resonator (SMR). By combining numerical and experimental methodologies, we prove that this novelty passive solution allows an efficient decoupling of elements of a phased-array coil. We demonstrate the ability of this technique to significantly reduce by more than 10dB the coupling preserving the quality of images compared to ideally isolated linear resonators on a spherical salty agar gel phantom in a 7T MRI scanner., (Copyright © 2016. Published by Elsevier Inc.)

We describe two experiments demonstrating that a cylindrical cloak formerly introduced for linear surface liquid waves works equally well for sound and electromagnetic waves. This structured cloak behaves like an acoustic cloak with an effective anisotropic density and an electromagnetic cloak with an effective anisotropic permittivity, respectively. Measured forward scattering for pressure and magnetic fields are in good agreement and provide first evidence of broadband cloaking. Microwave experiments and 3D electromagnetic wave simulations further confirm reduced forward and backscattering when a rectangular metallic obstacle is surrounded by the structured cloak for cloaking frequencies between 2.6 and 7.0 GHz. This suggests, as supported by 2D finite element simulations, sound waves are cloaked between 3 and 8 KHz and linear surface liquid waves between 5 and 16 Hz. Moreover, microwave experiments show the field is reduced by 10 to 30 dB inside the invisibility region, which suggests the multi-wave cloak could be used as a protection against water, sonic or microwaves.

Background: Acute cervical adenitis can evolve into suppurative cervical lymphadenitis and may sometimes be associated with infection of the retropharyngeal and parapharyngeal spaces (i.e., retropharyngeal and poststyloid parapharyngeal abscesses). This study aimed to describe the clinical presentation of acute cervical lymphadenitis and infections of the retropharyngeal and parapharyngeal spaces in children and examine the management of these conditions., Methods: This was a retrospective study including children from 3 months to 18 years old who were hospitalized in the Pediatric Department of the Centre-Intercommunal-de-Créteil between January 2003 and May 2010. Selected cases were based on the diagnosis of acute cervical lymphadenitis, suppurative cervical lymphadenitis, or infections of the retropharyngeal or parapharyngeal spaces. Case history, clinical signs, laboratory tests, imaging, treatment and clinical course were collected from patient charts., Results: We included 75 children (54 males [72%]); 62 (83%) were < 6 years old. Diagnoses were acute cervical lymphadenitis in 43 patients (57%), suppurative cervical lymphadenitis in 13 (17%), retropharyngeal or poststyloid parapharyngeal abscess in 18 (24%) and cervical necrotizing fasciitis in 1 (1%). In total, 72 patients (96%) presented fever and 34 (45%) had torticollis. Suppurative cervical lymphadenitis or abscesses of the retropharyngeal or poststyloid parapharyngeal spaces was significantly higher for children with than without torticollis (52.9% vs. 4.8%, p < 0.001). In all, 21 patients among the 44 > 3 years old (48%) underwent a rapid antigen detection test (RADT) for group A beta-hemolytic Streptococcus pyogenes; results for 10 were positive (48%). Contrast-enhanced CT scan of the neck in children with torticollis (n = 31) demonstrated an abscess in 21 (68%). Fine-needle aspiration was performed in 8 patients (11%) and 8 (11%) required surgical drainage. Bacteriology was positive in 8 patients (11%), with a predominance of Staphylococcus aureus and S. pyogenes. All patients received intravenous antibiotics and the outcome was favorable regardless of surgery. Recurrence was observed in only 1 case among the 34 patients with a follow-up visit after discharge., Conclusion: Our data suggest that presentation with cervical lymphadenitis associated with fever and torticollis requires evaluation by contrast-enhanced CT scan. Furthermore, abscess drainage should be restricted to the most severely affected patients who do not respond to antibiotic therapy.

Bacterial spores have a strong resistance to both chemical and physical hurdles and create a risk for the food industry, which has been tackled by applying high thermal intensity treatments to sterilize food. These strong thermal treatments lead to a reduction of the organoleptic and nutritional properties of food and alternatives are actively searched for. Innovative hurdles offer an alternative to inactivate bacterial spores. In particular, recent technological developments have enabled a new generation of high pressure homogenizer working at pressures up to 400 MPa and thus, opening new opportunities for high pressure sterilization of foods. In this short review, we summarize the work conducted on (ultra) high pressure homogenization (U)HPH to inactivate endospores in model and food systems. Specific attention is given to process parameters (pressure, inlet, and valve temperatures). This review gathers the current state of the art and underlines the potential of UHPH sterilization of pumpable foods while highlighting the needs for future work.

Bacterial spores are a major concern for food safety due to their high resistance to conventional preservation hurdles. Innovative hurdles can trigger bacterial spore germination or inactivate them. In this work, Geobacillus stearothermophilus spore high pressure (HP) germination and inactivation mechanisms were investigated by in situ infrared spectroscopy (FT-IR) and fluorometry. G. stearothermophilus spores' inner membrane (IM) was stained with Laurdan fluorescent dye. Time-dependent FT-IR and fluorescence spectra were recorded in situ under pressure at different temperatures. The Laurdan spectrum is affected by the lipid packing and level of hydration, and provided information on the IM state through the Laurdan generalized polarization. Changes in the -CH2 and -CH3 asymmetric stretching bands, characteristic of lipids, and in the amide I' band region, characteristic of proteins' secondary structure elements, enabled evaluation of the impact of HP on endospores lipid and protein structures. These studies were complemented by ex situ analyses (plate counts and microscopy). The methods applied showed high potential to identify germination mechanisms, particularly associated to the IM. Germination up to 3 log10 was achieved at 200 MPa and 55 °C. A molecular-level understanding of these mechanisms is important for the development and validation of multi-hurdle approaches to achieve commercial sterility., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Using PWM-driven immunoglobulin synthesis, we studied the regulatory effects of the peripheral blood T-lymphocyte subpopulations defined by the E10 antigen. This previously described antigen (E10) is present on 60% of TPBL, of T4+, and of T8+ cells. The helper activity on PWM-driven B-cell differentiation appears to be highly increased in E10- T cells. This higher capacity does not apparently reflect a different susceptibility to suppressor influences as comparable results were obtained when such suppressor influences are minimized either by removal of T8+ cells from E10- and E10+ T cells, or by removal of monocytes from responding B-cell populations. In contrast, the relative function of T-cell subsets defined by the related antigen 3A1 are influenced by the presence of suppressor cells. It is only in the presence of both T8+ cells and monocytes that 3A1+ cells exhibit a higher inducer effect. Our results suggest that E10 and 3A1 antigens--although showing strong distribution homologies--define different regulatory T-cell populations.