41 research outputs found
Comparison of SARS-cov-2 RdRp protein with SARS-cov RdRp protein
The World Health Organization (WHO) declared, on January 30, 2020, a public health emergency of international scope because of the emergence of a new virus called SARS-cov-2. This new virus belongs to the coronavirus family and has a protein called RNA-dependent RNA polymerase (RdRp) which is responsible for the replication of viral RNA. RdRp protein is one of the most primary targets for antiviral drug discoveries. The aim of this paper was to compare the amino acid sequence of the RdRp of SARS-cov-2 with that of SARS-cov. Thus, we found that there is a 96% sequence similarity between them. Indeed, there is only a difference at the level of 32 amino acids. Interestingly, only one residue at C Motif and two residues at D Motif are different. However, all the residues of the motifs A, B, E, F and G are 100% identical with those of SARS-cov-RdRp
Chemical and morphological characterization
Funding Information: The authors would express their sincere thanks to the Moroccan Center for Analysis and Characterization (CAC) affiliated to Cadi Ayyad University, for providing some sample characterizations. Publisher Copyright: © 2022This work aims to study the physical, chemical, and thermal properties of natural fibers extracted from the Pennisetum alopecuroides plant. The study was carried out on raw and treated fibers to assess improvements that facilitate future uses in composites. The alkaline treatment was carried out using NaOH with different concentrations (1, 3, 5, and 10%) for 2 hours. Hydrothermal treatment was performed at different immersion times in a water bath at 100°C. The chemical composition of Pennisetum alopecuroides fibers, such as cellulose, hemicellulose, lignin, and ash contents, was evaluated. The structure of the fiber was analyzed by FTIR, SEM, and X-ray diffraction. Thermogravimetric analysis (TGA) is used to study the thermal stability of the fiber. The density was also investigated with the pycnometric methode. The results showed that a concentration of 3% NaOH during the 2h is the most suitable solution to treat the P.alopecuroides fiber, but the hydrothermal treatment for 1h at 100°C is also effective for this fiber. The treated fibers seem viable to be used as reinforcement for composites production, namely to achieve goals of energy efficiency.publishersversionepub_ahead_of_prin
Intérêt de l’enclouage centromédullaire dans les fractures du quart distal de la jambe: à propos de 30 cas
Les fractures du quart distal de la jambe, sont des fractures dont le trait est situé au niveau du quart inférieur du tibia. Elles sont réputées graves et posent à la fois des problèmes de consolidation, de contention et de stabilité. Nous présentons l'expérience du service de traumatologie orthopédie de l'Hôpital militaire Avicenne de Marrakech, concernant 30 fractures fermées du quart inférieur de la jambe, sur une période de 10 ans (de Janvier 2001 à Décembre 2010) ayant reçu un enclouage centromédullaire. Le montage était verrouillé à 80% des cas et simple dans les autres cas. La moyenne d'âge de nos patients était de 36 ans. Il existait une nette prédominance masculine avec 27 hommes pour 3 femmes. La consolidation a été obtenue dans un délai normal de 17 semaines en moyenne et les résultats fonctionnels était satisfaisants. Un seul cas d'infection est survenu à 6 mois du geste chirurgical soit 3,3% et aucune autre complication n'a été mentionnée. Un cal vicieux a été retrouvé chez 30% de nos patients. Nos données épidémiologiques et nos résultats sont presque identiques à ceux de la littérature. Quant aux résultats angulaires, ils sont nettement inférieurs aux séries de plaques, à l'opposé, leurs résultats infectieux portent à la prudence et certains séries de clous rapportent d'excellents résultats angulaires à condition d'avoir un montage stable. A la lumière de ces résultats, nous sommes en droit de conclure au grand intérêt d'élargir les indications classiques de l'enclouage centromédullaire verrouillé à la prise en charge des fractures du quart distal de la jambe, à condition d'avoir un montage stable par un double verrouillage distal et une ostéosynthèse primaire des fractures distales de la fibula.Mots clés: Fracture du quart inférieur, jambe, enclouage centromédullaire, plaque visséeEnglish Title: Role of centro-medullary nailing in fractures of the distal quarter of the leg: about 30 casesEnglish AbstractThe fractures of the distal quarter of the leg are characterized by fracture line located at the level of the lower quarter of the tibia, according to Gerard and Evrard definition [1]. They are serious and pose problems for consolidation, immobilization and stability. We here describe our experience in the Department of Orthopaedics and Traumatology at the Avicenne Military Hospital, Marrakech. We report 30 cases of closed fractures of the lower quarter of the leg treated with centro-medullary nailing over a period of 10 years (January 2001-December 2010). Locked nailing was performed in 80% of cases and simple nailing was performed in the other cases. The average age of patients was 36 years. There was a clear male predominance (27 men, 3 women). The average time for consolidation was 17 weeks and functional outcomes were satisfactory. A single case of infection occurred 6 months after surgery (3.3%) and no other complication was reported. Malunion was detected in 30% of patients. Our epidemiological data and results were almost identical to those in the literature. Angular results were significantly lower than those obtained with the series of plates. By contrast, data on infections called for caution and some nails produced excellent angular results when nail fixation was stable. In the light of these results, codified indications for locked centro-medullary nailing should be extended to the fractures of the lower quarter of the leg, provided that stable fixation using double screw distal locking and primary osteosynthesis of distal fibula fractures are performed.Keywords: Fractures of the lower quarter, leg, centro-medullary nailing, screwed plat
Postero-apical thoracic schwannoma with cervical extension resected by complete video-assisted thoracoscopic surgery
Schwannomas or neurilemmomas are benign tumors developed from the peripheral nervous system. Complete video-assisted thoracic surgery (cVATS) has set itself over the years as the preferred approach for the removal of small mediastinal neurogenic tumors. However, in case of apical location, complete VATS seems challenging because of proximity with the subclavian artery and/or elements of the brachial plexus. In case of a cVATS procedure, some authors prefer enucleation instead of resection, with a higher risk of relapse. We present two cases of cVATS resection of thoracic apical schwannomas
Intracystic Papillary Carcinoma of the Breast: Report of Three Cases and Literature Review
Intracystic papillary carcinoma is a rare malignant tumor of the breast. It occurs communally in postmenopausal women. Clinically it can be asymptomatic or manifested by a breast mass or a nipple discharge. On imaging intracystic papillary carcinoma has usually benign features. Pathologic diagnosis can be difficult at classical histological examination and identification of myoepithelial cells layer by immunohistochemical study can be useful. In the majority of cases of pure intracystic papillary carcinoma, conservative management is possible. Adjuvant therapy is still controversial and prognosis is excellent. We report three cases of intracystic papillary carcinoma diagnosed on immunohistochemical examination and managed with conservative surgery
Interest of Surgical Treatment of Per-Trochanteric Fractures by Gamma Nail: About 100 Cases
Gamma nail closed osteosynthesis has surpassed several methods previously used in the treatment of fractures in the trochanteric region.
The objective of the research was to carry out an epidemiological study and to assess the evolutionary profile of patients with per-trochanteric fracture treated with gamma nail.
Materials and methods. In this retrospective study, we report the experience of the Traumatology-Orthopedics Service II of the Military Teaching Hospital Mohamed V-Rabat, in the treatment of per-trochanteric fractures by gamma nail in 100 cases, collected between January 2011 and March 2016.
Results. The average age of our patients was 68 years, with a male predominance of 67%. The most reported etiology (92% of cases) was simple drop. Stable fractures were the most common (81%), with a predominance of simple per-trochanteric fractures. The average response time was 24 hours, the average duration of the surgical procedure was 45 minutes. The rate of infectious complications was 1%; the rate of mechanical complications was 1%. The functional results were excellent and good in 95% of cases. The average consolidation time was 8 weeks.
Conclusions. Trochanteric fracture is a delayed emergency which is seen primarily in the elderly. The gamma nail represents one of the latest improvements in implants for the treatment of these fractures. We report a series of 100 cases of trochanteric fractures treated surgically by gamma nail. The functional results were very encouraging compared to those reported in the literature.
 
Bone metastases revealing hepatocellular carcinoma. About 3 cases
Introduction : Les métastases osseuses du carcinome hépatocellulaire sont rares et exceptionnellement révélatrices ; leurs sièges électifs sont les vertèbres, les côtes et le sternum. Observations : Nous rapportons trois cas de métastases osseuses révélatrices d’un CHC chez des patients porteurs d’hépatopathie chronique. À travers ces trois observations et une revue de la littérature, nous essaierons de décrire cette entité clinique particulière et de faire le point sur les différentes modalités thérapeutiques disponibles. Conclusion : Les métastases osseuses révélant un CHC sont rares ; toutefois, il faut les évoquer devant toute lésion osseuse lytique, surtout chez les patients porteurs d’hépatopathie chronique. Vu leur pronostic sombre, leur traitement est palliatif, visant essentiellement à améliorer la qualité de vie des patients.Introduction: Bone metastases of hepatocellular carcinoma are rare and exceptionally revealing. Their elective seats are the vertebrae, ribs and sternum. Case report: We report three cases of bone metastases as the initial presentation of hepatocellular carcinoma in patients with chronic liver disease. Through these three cases and a literature review, we will try to describe this particular clinical entity and take stock of the different treatment now available. Conclusion: Bone metastases revealing HCC are rare. However, it must evoke before any lytic bone lesions, especially in patients with chronic liver disease. Due to a poor prognosis, treatment is palliative, aimed primarily at improving the quality of patients’life
Contribution of magnetic resonance imaging in the diagnosis of talus skip metastases of Ewing's sarcoma of the calcaneus in a child: a case report
<p>Abstract</p> <p>Introduction</p> <p>Ewing's sarcoma of the calcaneus is rare. About thirty cases with calcaneus involvement have been reported in the literature. Talus skip metastases have rarely been described in the available literature</p> <p>Case presentation</p> <p>We report a case of a 14-year-old Moroccan boy, who presented with Ewing's sarcoma of his right calcaneus, diagnosed by swelling of the calcaneus evolving over a year. Radiography, computed tomography and magnetic resonance imaging showed an important tumoral process of the calcaneus and talus skip metastases. The diagnosis was confirmed with histology after a biopsy. In spite of amputation and postoperative chemotherapy, our patient died six months later due to secondary respiratory distress after lung metastasis.</p> <p>Conclusion</p> <p>Imaging, especially magnetic resonance, is important in the diagnosis of Ewing sarcoma and skeletal skip metastases. Treatment of Ewing's sarcoma consists of chemotherapy, radiation therapy and surgical resection depending on the stage and extent of the disease. With the exception of lesions in the calcaneus, the prognosis for disease-free survival of Ewing's sarcoma of the foot is excellent.</p
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
Online Parameter Identification for Supercapacitor State-of-Health Diagnosis for Vehicular Applications
International audienceIn power electronic applications, aging of the electric double layer capacitors (EDLCs) is considered as a serious issue since it may lead to failure. Their degradation is usually evaluated by an increase of the internal resistance or a decrease of the equivalent capacitance. These aging indicators have a good correlation with the supercapacitor's state-of-health (SoH). Generally, SoH is measured by electrochemical impedance spectroscopy (EIS). However, this technique must be performed offline and requires interruption of the system's operation. In this paper, a sliding mode observer is designed to estimate online the EDLC's aging indicators. Unlike several online estimators, the supercapacitor's parameters are considered as a nonlinear random distribution with external noises which yields accurate estimation. In addition, the relationship between the capacitance and the bias voltage is considered to be nonlinear. Lyapunov stability analysis is also provided. The proposed approach is validated experimentally using a standardized dynamic current profile. Furthermore, comparison against EIS is carried out for different aging phases and under different environmental temperature conditions