MBSE Applied to an Aerospace ‘Force Fighting’ Application

International audienceThe aerospace industry is a domain where system engineering, and in particular Model Based System Engineering (MBSE), has been adopted extensively. Based on a feedback of the ongoing development of a technical use case, this paper provides a high level view of MBSE state-of-the-art and current state-of-practice as provided through the Dassault Systèmes (DS) Product Lifecycle Management (PLM) solutions

Surgical hip dislocation with relative femoral neck lengthening and retinacular soft-tissue flap for sequela of Legg-Calve-Perthes disease.

OBJECTIVE Correction of post-LCP (Legg-Calve-Perthes) morphology using surgical hip dislocation with retinacular flap and relative femoral neck lengthening for impingent correction reduces the risk of early arthritis and improves the survival of the native hip joint. INDICATIONS Typical post-LCP deformity with external and internal hip impingement due to aspherical enlarged femoral head and shortened femoral neck with high riding trochanter major without advanced osteoarthritis (Tönnis classification ≤ 1) in the younger patient (age < 50 years). CONTRAINDICATIONS Advanced global osteoarthritis (Tönnis classification ≥ 2). SURGICAL TECHNIQUE By performing surgical hip dislocation, full access to the hip joint is gained which allows intra-articular corrections like cartilage and labral repair. Relative femoral neck lengthening involves osteotomy and distalization of the greater trochanter with reduction of the base of the femoral neck, while maintaining vascular perfusion of the femoral head by creation of a retinacular soft-tissue flap. POSTOPERATIVE MANAGEMENT Immediate postoperative mobilization on a passive motion device to prevent capsular adhesions. Patients mobilized with partial weight bearing of 15 kg with the use of crutches for at least 8 weeks. RESULTS In all, 81 hips with symptomatic deformity of the femoral head after healed LCP disease were treated with surgical hip dislocation and offset correction between 1997 and 2020. The mean age at operation was 23 years; mean follow-up was 9 years; 11 hips were converted to total hip arthroplasty and 1 patient died 1 year after the operation. The other 67 hips showed no or minor progression of arthrosis. Complications were 2 subluxations due to instability and 1 pseudarthrosis of the lesser trochanter; no hip developed avascular necrosis

Eye-Sat: A 3U Student CubeSat from CNES Packed with Technology

Eye-Sat will observe the Zodiacal light, the Sun light scattered by interplanetary dust. It is a diffuse and faint white glow. Equipped with its small home-made telescope, this 3U CubeSat will measure the zodiacal light’s intensity and linear polarization ratio. The payload’s optics has a focal length of 50 mm and a diameter of 25 mm for a field of view of +/- 6.5°. Two rotating wheels bear spectral and polarizing filters. For one year Eye-Sat will produce more than 500 GB of data which will be downloaded to the ground thanks to a high data rate X-band link. Moreover, scientific objectives impose severe requirements on the attitude determination and control system such as a 0.25° 3-axis pointing accuracy. To fulfil these requirements, Eye-Sat comprises a star tracker and four reaction wheels. Eye-sat will also welcome new technologies on board to demonstrate their applicability in space environment and to test their in-orbit performances: - C&DH module will combine a dual-core ARM9 microprocessor (CPU frequency up to 1GHz) and a FPGA - Flight software will be based on Time and Space Partitioning technology - S-band TTC transceiver - X-band transmitter for scientific data - Solar panels will be deployed by self-blocking and self-deployable composite hinges - Hold-on and Release Mechanisms based on the thermal knife concept - 3DPlus camera with a CMOS detector from CMOSIS - Innovative black coating from Cilas Eye-Sat is a Student CubeSat which belongs to JANUS, a CNES’ program that supports French Universities in developing their CubeSat projects. The specificity of Eye-Sat is that it has been developed within the French Space Agency since 2012, with more than 200 students involved. After passing a successful qualification review before a board of CNES agents in October 2018, the project team is now in the Assembling, Integration and Validation phase with the flight model. Launch is due on October/November 2019, on a Soyouz rocket from French Guyana, with COSMOS Sky-Med from the Italian Space Agency and Cheops from the European Space Agency

Revision of a Failed Primary Total Hip Arthroplasty following Excessive Reaming with a Medial Cup Protrusion.

Background and Objectives: Atraumatic intrapelvic protrusion of the acetabular component following excessive reaming of the acetabulum with a far medial positioning of the cup is a rare, but serious complication of a total hip arthroplasty (THA). This study analyzes the factors contributing to this uncommon complication and presents the outcome after the revision surgery using the Ganz reinforcement ring combined with a bone graft and plating of the posterior column and/or screws for the anterior column. Materials and Methods: A retrospective case series study with seven patients (four males, mean age 76 ± 10 years (60-86)) that underwent a revision THA within 24 ± 17 days (5-60) after an atraumatic periprosthetic acetabular fracture with a medial cup protrusion was performed. All fractures were reconstructed with a Ganz reinforcement ring and bone graft with a mean follow-up of 1.7 ± 1.7 years (0.5-5). Radiographs were evaluated for the following: (i) cup positioning immediately after the primary THA and the revision surgery, (ii) cup migration in the follow-up, and (iii) fracture healing. Results: The position of the acetabular component as assessed on the postoperative radiographs after the index surgery and before the complete medial cup protrusion showed a cup placement beyond the ilioischial line indicative of a fracture of the medial wall. The revision surgery with the reconstruction of the medial wall with a Ganz reinforcement ring combined with a bone graft restored in the presented cases the center of rotation in the horizontal direction with a statistical significance (p &lt; 0.05). During the follow-up, there was no aseptic loosening with the relevant cup migration or significant change in the position of the acetabular cup at the final follow-up (p &gt; 0.05) after the revision. All seven fractures and bone grafts realized a bone union until the latest follow-up. Conclusions: Following excessive reaming, the acetabular component was placed too far medially and resulted in an intrapelvic cup protrusion. An unstable cup following a fracture of the medial wall was evident on the immediate postoperative radiographs. In the case of the medial wall perforation with an intrapelvic cup protrusion after the primary THA, the reconstruction with a Ganz reinforcement ring was a successful treatment option resulting in the fracture healing and a stable cup positioning. Surgeons should be aware of that rare and probably underreported complication and restore the anatomic center of rotation by treating the defect intraoperatively

A Bibliometric Analysis of Fragility Fractures: Top 50.

Background and Objectives: The population is aging and fragility fractures are a research topic of steadily growing importance. Therefore, a systematic bibliometric review was performed to identify the 50 most cited articles in the field of fragility fractures analyzing their qualities and characteristics. Materials and Methods: From the Core Collection database in the Thomson Reuters Web of Knowledge, the most influential original articles with reference to fragility fractures were identified in February 2021 using a multistep approach. Year of publication, total number of citations, average number of citations per year since year of publication, affiliation of first and senior author, geographic origin of study population, keywords, and level of evidence were of interest. Results: Articles were published in 26 different journals between 1997 and 2020. The number of total citations per article ranged from 12 to 129 citations. In the majority of publications, orthopedic surgeons and traumatologists (66%) accounted for the first authorship, articles mostly originated from Europe (58%) and the keyword mostly used was "hip fracture". In total, 38% of the articles were therapeutic studies level III followed by prognostic studies level I. Only two therapeutic studies with level I could be identified. Conclusions: This bibliometric review shows the growing interest in fragility fractures and raises awareness that more high quality and interdisciplinary studies are needed

EyeSat: A Great Student Adventure Within the French Space Agency Leading Up to Lessons Learned From Orbit

EyeSat has been a tremendous, challenging and successful student project. With 250 students over 7 years, CNES has achieved to put in orbit a 3U CubeSat that carries tens of state-of-the art innovative nanosatellite subsystems resulting from R&D programs carried out within the French space ecosystem. Launched in December 18, 2019, EyeSat has proved to be fully functional in orbit and has started its mission to map the intensity and the polarization direction of the zodiacal light. Housekeeping data, acquired over the past 5 months, has been analyzed by the team. Precious comparisons have been made between design and simulation results on the one hand and actual data on the other. Now, the private company U-Space, created in 2018, leverages those lessons learned from EyeSat and provides space missions based on high-performance nanosatellites

Identification of fosa8, a plasmid-encoded fosfomycin resistance determinant from Escherichia coli, and its origin in Leclercia adecarboxylata

A plasmid-located fosfomycin resistance gene, fosA8, was identified from a CTX-M- 15-producing Escherichia coli isolate recovered from urine. Identification of this gene was obtained by whole-genome sequencing. It encoded FosA8, which shares 79% and 78% amino acid identity with the most closely related FosA2 and FosA1 enzymes, respectively. The fosA8 gene was located on a transferable 50-kb plasmid of IncN type encoding high-level resistance to fosfomycin. In silico analysis and cloning experiments identified fosA8 analogues (99% identity) in the genome of Leclercia decarboxylata, which is an enterobacterial species with natural resistance to fosfomycin. This finding adds L. decarboxylata to the list of enterobacterial species that are a reservoir of fosA-like genes which have been captured from the chromosome of a progenitor and are then acquired by E. coli

Colistin resistance in Parisian inpatient faecal Escherichia coli as the result of two distinct evolutionary pathways

Beyond plasmid-encoded resistance (mcr genes) prevalence in strain collections, large epidemiological studies to estimate the human burden of colistin-resistant Escherichia coli gut carriage are lacking.Objectives: To evaluate the prevalence of colistin-resistant E. coli carriage in inpatients and decipher the molecular support of resistance and the genetic background of the strains.Methods: During a 3 month period in 2017, we prospectively screened patients in six Parisian hospitals for rectal carriage of colistin-resistant E. coli using a selective medium, a biochemical confirmatory test and MIC determination. WGS of the resistant strains and their corresponding plasmids was performed.Results: Among the 1217 screened patients, 153 colistin-resistant E. coli strains were isolated from 152 patients (12.5%). The mcr- 1 gene was identified in only seven isolates (4.6%) on different plasmid scaffolds. The genetic background of these MCR-1 producers argued for an animal origin. Conversely, the remaining 146 colistin-resistant E. coli exhibited a phylogenetic distribution corresponding to human gut commensal/clinical population structure (B2 and D phylogroup predominance); 72.6% of those isolates harboured convergent mutations in the PmrA and PmrB proteins, constituting a two-component system shown to be associated with colistin resistance.Conclusions: We showed that the occurrence at a high rate of colistin resistance in human faecal E. coli is the result of two distinct evolutionary pathways, i.e. the occurrence of chromosomal mutations in an endogenous E. coli population and the rare acquisition of exogenous mcr-1- bearing strains probably of animal origin. The involved selective pressures need to be identified in order to develop preventative strategies

Efficacy of trabectedin in metastatic solitary fibrous tumor

Solitary fibrous tumor is a rare tumor type and has an unpredictable course. Local recurrence rate varies between 9 and 19%, and rate of metastatic involvement between 0 and 36 %. It is characterized by a typical architecture and immuno-histochemistry tests. The most important prognostic factor is the complete resection of primary tumor. Treatment of recurrences is not clearly established. If a solitary fibrous tumor is too advanced to allow surgical resection, radiotherapy and chemotherapy may be used. The most often used drugs are doxorubicine and\or ifosfamide. We report the case of man with metastatic solitary fibrous tumor treated with trabectedin, administered at a dose of 1.5 mg/m² every 3 weeks. After 3 cycles, metastases had significantly decreased. Recurrence of the disease was demonstrated 8 months after the start of trabectedin. This case shows that trabectedin is a possible treatment option

Beta-lactam antibiotics: from antibiosis to resistance and bacteriology

This review focuses on the era of antibiosis that led to a better understanding of bacterial morphology, in particlar the cell wall component peptidoglycan. This is an effort to take readers on a tour de force from the concept of antibiosis, to the serepidity of antibiotics, evolution of betalactam development, and the molecular biology of antibiotic resistance. These areas of research have culminated in a deeper understanding of microbiology, particularly in the area of bacterial cell wall synthesis and recycling. In spite of this knowledge, which has enabled design of new even more effective therapeutics to combat bacterial infection and has provided new research tools, antibiotic resistance remains a worldwide health care problem