Clinical and Histologic Evaluation of Using Block Xenograft Combined With Leukocyte-Platelet Rich Fibrin (L-PRF) Versus Intraoral Autogenous Bone Block Graft With L-PRF in Treating Localized Ridge Defects: A Randomized Clinical Trial

Background: Augmentation of vertical bone defects remains the corner stone in periodontal tissue engineering. The amount and quality of alveolar bone available in all dimensions affects the success of dental implants for restoration of edentulous areas. Adequate and healthy bone supports the degree of osseointegration which in turn affects the long-term success of oral implants. The primary aim of the study was to histologically evaluate autogenous block grafts versus synthetic block grafts for the treatment of atrophic vertical and horizontal bony defects (Siebert Class III) in the anterior esthetic zone of the mouth. The secondary aim was to clinically and radiographically evaluate the outcomes of the procedure. Methods: This was a randomized controlled clinical study with a statistically determined sample size of 10 patients per group and a total of 20 patients in both groups. Patients with vertical and horizontal bone loss were enrolled from the Department of Oral Medicine, Periodontology, and Oral Diagnosis of Ain Shams University and Misr International University. Bone augmentation procedures were performed using two techniques: autogenous bone block graft and xenograft bone block graft both with leukocyte-platelet rich fibrin (L-PRF). Results: Both autogenous and xenograft blocks in conjunction with L-PRF had a significant effect on vertical bone augmentation in cases of atrophic ridges in the esthetic region. Conclusion: Both autogenous and xenograft bone blocks in conjunction with L-PRF have a significant effect on vertical bone augmentation in cases of atrophic ridges in the esthetic region

Beamforming and Device Selection Design in Federated Learning with Over-the-air Aggregation

Federated learning (FL) with over-the-air computation can efficiently utilize the communication bandwidth but is susceptible to analog aggregation error. Excluding those devices with weak channel conditions can reduce the aggregation error, but it also limits the amount of local training data for FL, which can reduce the training convergence rate. In this work, we jointly design uplink receiver beamforming and device selection for over-the-air FL over time-varying wireless channels to maximize the training convergence rate. We reformulate this stochastic optimization problem into a mixed-integer program using an upper bound on the global training loss over communication rounds. We then propose a Greedy Spatial Device Selection (GSDS) approach, which uses a sequential procedure to select devices based on a measure capturing both the channel strength and the channel correlation to the selected devices. We show that given the selected devices, the receiver beamforming optimization problem is equivalent to downlink single-group multicast beamforming. To reduce the computational complexity, we also propose an Alternating-optimization-based Device Selection and Beamforming (ADSBF) approach, which solves the receiver beamforming and device selection subproblems alternatingly. In particular, despite the device selection being an integer problem, we are able to develop an efficient algorithm to find its optimal solution. Simulation results with real-world image classification demonstrate that our proposed methods achieve faster convergence with significantly lower computational complexity than existing alternatives. Furthermore, although ADSBF shows marginally inferior performance to GSDS, it offers the advantage of lower computational complexity when the number of devices is large.Comment: 12 pages, 8 figure

Tempol improves optic nerve histopathology and ultrastructures in cisplatin-induced optic neuropathy in rats by targeting oxidative stress—Endoplasmic reticulum stress—Autophagy signaling pathways

IntroductionOptic neuropathy is an affection of the optic neurons, which ends with blindness and occurs either primarily due to direct affection of the optic nerve or secondarily as a complication of chronic diseases and/or adverse effects of their therapy. The search for novel therapeutic tools is crucial in addressing the limited therapeutic approaches for optic neuropathy. Therefore, the present study was developed to investigate the possible ameliorative effect of tempol against cisplatin-induced optic neuropathy and its underlying mechanism.MethodsForty-eight adult male albino Wistar rats were divided into four equal groups—control, tempol (TEM), cisplatin (CIS), and tempol and cisplatin combined (TEM+CIS). Optic nerve oxidative stress (MDA, SOD, and GPx), gene expression of endoplasmic reticulum stress (ATF-6, XBP-1, BIP, CHOP, and JNK), autophagy 6 (LC3, Beclin-1, and p62) markers, nerve growth factor-1, immunohistochemical expression of (LC3 and p62), histopathological, and electron microscopic examination were performed.ResultsHistopathological and ultrastructure examination validated that cisplatin caused optic neuropathy by inducing oxidative stress, upregulating ER stress markers, and downregulating autophagy markers, and NGF-1 expression. TEM + CIS showed improvement in optic nerve structure and ultrastructure along with oxidative stress, ER stress mRNA, autophagy (immunohistochemical proteins and mRNA) markers, and nerve growth factor mRNA expression.ConclusionsBased on previous findings, tempol represents a valid aid in cisplatin-induced optic neuropathy by implicating new molecular drug targets (ER stress and autophagy) for optic neuropathy therapy

Interaction fluide-structure de rotors flexibles fortement déformés

Ce travail concerne l'étude, expérimentale et analytique, de l'interaction fluide-structure (FSI) de rotors flexibles fortement déformés. Les rotors, de par leurs nombreuses applications, sont souvent flexibles, par exemple les grandes pales d'éoliennes, les pales élancées d'hélicoptères et les rotors de drones de petite taille. La compréhension de la FSI des rotors flexibles permettrait d'évaluer les différents risques opérationnels qui pourraient survenir en raison de la déformation des pales de rotor. En outre, elle permettrait d'utiliser la propriété de flexibilité pour augmenter la résistance mécanique du rotor et améliorer ses performances. Dans un premier temps, ce travail s'intéresse à l'exploration expérimentale des différents phénomènes de FSI qui pourraient survenir lors du fonctionnement des rotors flexibles. Dans l'étude expérimentale, les rotors sont testés dans un canal d'eau. Les rotors testés sont à petite échelle et sont constitués de pales à géométrie rectangulaire simplifiée. La déformation des pales et le sillage sont mesurés à l'aide de techniques optiques. Cette campagne expérimentale a montré différents comportements de courbure des pales en fonction des paramètres de conception et d'exploitation. De plus, différentes instabilités apparaissent pendant les essais, de la divergence de la pale du rotor aux fluctuations instables de grande amplitude et de basse fréquence. Un autre point d'intérêt de cette étude est la modélisation aéroélastique des fortes déformations d'une pale de rotor flexible. La préoccupation principale dans ce travail est l'étude de l'aéroélasticité statique. Pour la modélisation de la structure de la pale, le modèle de Kirchhoff à tige mince est utilisé, tandis que pour la modélisation du fluide, le modèle de tourbillon hélicoïdal est employé. Enfin, la validation du modèle aéroélastique est effectuée à l'aide des résultats expérimentaux obtenus dans le cadre de cette étudeThis work is concerned with the study, experimental and analytical, of the fluid-structure interaction (FSI) of strongly deforming flexible rotors. Rotors through their wide applications are often flexible, for example large wind turbine blades, slender helicopter blades and small scale drones rotors. Understanding the FSI of flexible rotors would allow the assessment of various operational risks that might arise due to the deformation of rotor blades, furthermore, it would allow the use of the flexibility property to increase the rotor mechanical strength and enhance its performance. Initially, this work is concerned with the experimental exploration of the various FSI phenomena that might arise during flexible rotors operation. In the experimental study, rotors are tested in a water channel. The tested rotors are small scale formed of blades with simplified rectangular geometry. The blade deformation and wake are measured using optical techniques. This experimental campaign showed various blade bending pattern behaviours depending on the design and operation parameters, furthermore, different instabilities arise during testing from divergence of rotor bladeto unsteady large amplitude low frequency fluctuations. Another point of interest of this study is the aeroelastic modelling of the strong deformations of a flexible rotor blade. The main concern in this work is the static aeroelasticity study. For the blade structure modelling, the Kirchhoff thin rod model is used while for the fluid modelling, a helical vortex model is employed. Finally, validation is carried out for the aeroelastic model using the experimental results obtained in this stud

Experimental investigation of flexible rotors in water

National audienc

Spectrum awareness for cognitive radio systems

Spectrum scarcity is an obstacle to deploy emerging high speed wireless services that require more frequency spectrum. Cognitive radio (CR) appears as a promising solution for the spectral congestion by allowing spectrum sharing between primary and secondary users in which optimum utilization of the available spectrum is achieved. Efficient coexistence between different users requires full knowledge of the activities in the spectrum of interest. Spectrum awareness is the terminology used to describe the techniques that detect the presence of signals in certain frequency bands, as well as identify the main parameters of such signals, e.g., modulation scheme. These two tasks are commonly referred by the terms spectrum sensing and signal identification, respectively. Blind signal identification was initially used by military applications, such as radio surveillance and electronic warfare, and has recently been extended to civilian applications. This problem becomes more challenging in multiple-input multiple-output (MIMO) scenarios due to the diverse transmission schemes that can be employed, e.g., spatial multiplexing (SM) and space-time block codes (STBCs). A large number of studies have been carried out for developing blind signal identification algorithms in single-input singleoutput (SISO) scenarios, including identification of the modulation format and recognition of single-carrier (SC) versus multicarrier transmissions. However, the problem of signal identification for MIMO systems remains at an incipient stage. In this dissertation, we develop novel algorithms to blindly identify the MIMO transmission scheme of the received signal. More specifically, in Chapters 2 and 3, we address the problem of identifying STBCs for the SC transmission. Unlike most of the work done to date, we show that STBC identification can be performed using a single receive antenna. Four algorithms are proposed in Chapter 2 to identify SM and Alamouti STBC. Then, the idea is extended to include additional STBCs in Chapter 3. The proposed algorithms show improved performance when compared with other algorithms in the literature. Moreover, neither modulation identification nor channel and noise power estimation are required by these algorithms. In Chapter 4 we investigate the identification of SM and Alamouti coded orthogonal frequency division multiplexing (OFDM) signals. A new discriminating feature and a novel decision criterion are developed. The proposed algorithm outperforms the algorithms in the literature with the advantages of requiring neither modulation identification nor channel and noise power estimation, and being more robust to the carrier frequency offset impairment. Furthermore, in Chapter 5, the problem of identifying SM and Alamouti SC frequency division multiple access (SC-FDMA) signals is studied when the receiver is equipped with a single antenna. To the best of our knowledge, this is the first work devoted to the identification of MIMO SC-FDMA signals. The theoretical performance analysis of the proposed algorithm is presented. Simulation results show the agreement between theoretical and simulation findings. The proposed algorithm requires neither modulation identification nor channel and noise power estimation. Finally, conclusions are drawn and possible extensions to signal identification in MIMO scenarios are discussed in Chapter 6

Caractérisation et analyse des déformations d’un rotor flexible dans l’eau

National audienc

Fluid–structure interaction of a flexible rotor in water

International audienc

Deformation and wake of a flexible rotor in water

International audienc

The effect of using the minimized cardio-pulmonary bypass Systems for Coronary Artery Bypass Grafting in diabetic patients

Abstract Introduction Multiple studies have shown a decrease in the inflammatory response with minimized bypass circuits leading to less complications and mortality rate. On the other hand, some other studies showed that there is no difference in post-operative outcomes. So, the aim of this study is to investigate the clinical benefits of using the Minimized cardiopulmonary Bypass system in Coronary Artery Bypass Grafting and its effect on postoperative morbidity and mortality in diabetic patients as one of the high-risk groups that may benefit from these systems. Methods This is a retrospective study that included 114 diabetic patients who underwent Coronary artery bypass grafting (67 patients with conventional cardiopulmonary bypass system and 47 with Minimized cardiopulmonary bypass system). The patients’ demographics, intra-operative characteristics and postoperative complications were compared between the two groups. Results Coronary artery bypass grafting was done on a beating heart less commonly in the conventional cardiopulmonary bypass group (44.78% vs. 63.83%, p = 0.045). There was no difference between the two groups in blood loss or transfusion requirements. Four patients in the conventional cardiopulmonary bypass group suffered perioperative myocardial infarction while no one had perioperative myocardial infarction in the Minimized cardiopulmonary bypass group. On the other hand, less patients in the conventional group had postoperative Atrial Fibrillation (4.55% vs. 27.5%, p = 0.001). The requirements for Adrenaline and Nor-Adrenaline infusions were more common the conventional group than the Minimized group. Conclusion The use of conventional cardiopulmonary bypass for Coronary Artery Bypass Grafting in diabetic patients was associated with higher use of postoperative vasogenic and inotropic support. However, that did not translate into higher complications rate or mortality