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40 results on '"Hammad, Karim"'

1. A Blockchain Policy and Charging Control Framework for Roaming in Cellular Networks

Author

Refaey, Ahmed, Hammad, Karim, Magierowski, Sebastian, and Hossain, Ekram

Subjects
Computer Science - Networking and Internet Architecture
Abstract

As a technology foundation of cryptocurrencies, blockchain enables decentralized peer-to-peer trading through consensus mechanisms without the involvement of a third party. Blockchain has been regarded as an auspicious technology for future cellular networks. It is able to provide solutions to problems related to mobile operators and user trust, embedded smart contracts, security concerns, pricing (e.g. for roaming), etc. When applying blockchain to cellular networks, there are significant challenges in terms of deployment and application, due to resource-constrained transactions. This article begins by introducing the basic concept of blockchain and then moves on to illustrate its benefits and limitations in the roaming system. Two models of roaming-based blockchain technologies are offered to show their suitability for cellular networks as opposed to traditional technology. Finally, potential issues and challenges of roaming-based blockchains are addressed and evaluated using the roaming use case in the EU.

Published
2019

3. Enhancing Progressive Collapse Resistance in Existing Buildings

Author

Hammad, Karim, Lotfy, Ibrahim, Naiem, Mohamed, Shehata, Hany Farouk, Editor-in-Chief, ElZahaby, Khalid M., Advisory Editor, Chen, Dar Hao, Advisory Editor, El Dimeery, Ibrahim, editor, Baraka, Moustafa, editor, Ahmed, Syed M., editor, Akhnoukh, Amin, editor, Anwar, Mona B., editor, El Khafif, Mahmoud, editor, Hanna, Nagy, editor, and Abdel Hamid, Amr T., editor

Published
2021
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5. An SoC Design for Future Mobile DNA Detection.

Author

Dawji, Yunus, Wu, Zhongpan, Beyene, Abel, Hammad, Karim, Ghafar-Zadeh, Ebrahim, and Magierowski, Sebastian

Abstract

Existing miniature DNA sequencing devices hold significant promise to serve as mobile/personal genomic analysis systems in the future. But a key challenge to this vision is the absence of adequate low-power bioinformatic computing ability within the sequencing device itself. In this letter, we discuss the design and demonstrate a system-on-chip (SoC) based on an accelerated RISC-V core for such a task. The chip was fabricated in 22-nm CMOS and executes almost $10\times $ faster than a commercial mobile processor on a DNA sequence detection task while achieving $200\times $ better energy efficiency. [ABSTRACT FROM AUTHOR]

Published
2024
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8. New Lidocaine-Based Pharmaceutical Cocrystals: Preparation, Characterization, and Influence of the Racemic vs. Enantiopure Coformer on the Physico-Chemical Properties

Author

Ma, Panpan, primary, Toussaint, Balthazar, additional, Roberti, Enrica Angela, additional, Scornet, Noémie, additional, Santos Silva, Axel, additional, Castillo Henríquez, Luis, additional, Cadasse, Monique, additional, Négrier, Philippe, additional, Massip, Stéphane, additional, Dufat, Hanh, additional, Hammad, Karim, additional, Baraldi, Cecilia, additional, Gamberini, Maria Cristina, additional, Richard, Cyrille, additional, Veesler, Stéphane, additional, Espeau, Philippe, additional, Lee, Tu, additional, and Corvis, Yohann, additional

Published
2023
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17. Chronic viral infection promotes efficient germinal center B cell responses

Author

Pinschewer, Daniel D., primary, Fallet, Bénédict, additional, Hao, Yi, additional, Florova, Marianna, additional, Cornille, Karen, additional, de los Aires, Alba Verge, additional, Zubani, Giulia Girelli, additional, Ertuna, Yusuf, additional, Greiff, Victor, additional, Menzel, Ulrike, additional, Hammad, Karim, additional, Merkler, Doron, additional, Reddy, Sai T., additional, Weill, Jean-Claude, additional, and Reynaud, Claude-Agnès, additional

Published
2020
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19. A Chemically Stable Fluorescent Mimic of Dihydroartemisinin, Artemether, and Arteether with Conserved Bioactivity and Specificity Shows High Pharmacological Relevance to the Antimalarial Drugs

Author

Sissoko, Abdoulaye, primary, Vásquez-Ocmín, Pedro, additional, Maciuk, Alexandre, additional, Barbieri, Daniela, additional, Neveu, Gaëlle, additional, Rondepierre, Laurine, additional, Grougnet, Raphaël, additional, Leproux, Pascale, additional, Blaud, Magali, additional, Hammad, Karim, additional, Michel, Sylvie, additional, Lavazec, Catherine, additional, Clain, Jérôme, additional, Houzé, Sandrine, additional, and Duval, Romain, additional

Published
2020
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21. Tolerogenic properties of liver macrophages in non‐alcoholic steatohepatitis

Author

Orci, Lorenzo A., primary, Kreutzfeldt, Mario, additional, Goossens, Nicolas, additional, Rubbia‐Brandt, Laura, additional, Slits, Florence, additional, Hammad, Karim, additional, Delaune, Vaihere, additional, Oldani, Graziano, additional, Negro, Francesco, additional, Clément, Sophie, additional, Gonelle‐Gispert, Carmen, additional, Buhler, Léo H., additional, Toso, Christian, additional, and Lacotte, Stéphanie, additional

Published
2020
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23. The prognostic value of expression of HIF1α, EGFR and VEGF-A, in localized prostate cancer for intermediate- and high-risk patients treated with radiation therapy with or without androgen deprivation therapy

Author

Weber Damien C, Tille Jean-Christophe, Combescure Christophe, Egger Jean-François, Laouiti Mahomet, Hammad Karim, Granger Perrine, Rubbia-Brandt Laura, and Miralbell Raymond

Subjects
Medical physics. Medical radiology. Nuclear medicine, R895-920, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282
Abstract

Abstract Purpose Androgens stimulate the production of hypoxia-inducible factor (HIF1α) and ultimately vascular endothelial growth factor (VEGF-A). Additionally, epithelial growth factor (EGF) mediates HIF1α production. Carbonic anhydrase IX (CAIX) expression is associated with tumor cell hypoxia in a variety of malignancies. This study assesses the prognostic relation between HIF1α, VEGF-A, EGF Receptor and CAIX expression by immunochemistry in diagnostic samples of patients with intermediate- and high-risk localized prostate cancer treated with radiation therapy, with or without androgen deprivation therapy (ADT). Materials and methods Between 1994 and 2004, 103 prostate cancer patients (mean age, 68.7 ± 6.2), with prostate cancer (mean PSA, 13.3 ± 3.7), were treated with radiation therapy (RT, median dose, 74 Gy). Fifty seven (55.3%) patients received ADT (median duration, 6 months; range, 0 – 24). Median follow-up was 97.6 months (range, 5.9 – 206.8). Results Higher EGFR expression was significantly (p = 0.04) correlated with higher Gleason scores. On univariate analysis, HIF1α nuclear expression was a significant (p = 0.02) prognostic factor for biological progression-free survival (bPFS). A trend towards significance (p = 0.05) was observed with EGFR expression and bPFS. On multivariate analysis, low HIF1α nuclear (p = 0.01) and high EGFR (p = 0.04) expression remained significant adverse prognostic factors. Conclusions Our study suggests that high nuclear expression of HIF1α and low EGFR expression in diagnostic biopsies of prostate cancer patients treated with RT ± ADT is associated with a good prognosis.

Published
2012
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24. Brain-resident memory T cells generated early in life predispose to autoimmune disease in mice

Author

Steinbach, Karin, primary, Vincenti, Ilena, additional, Egervari, Kristof, additional, Kreutzfeldt, Mario, additional, van der Meer, Franziska, additional, Page, Nicolas, additional, Klimek, Bogna, additional, Rossitto-Borlat, Irène, additional, Di Liberto, Giovanni, additional, Muschaweckh, Andreas, additional, Wagner, Ingrid, additional, Hammad, Karim, additional, Stadelmann, Christine, additional, Korn, Thomas, additional, Hartley, Oliver, additional, Pinschewer, Daniel D., additional, and Merkler, Doron, additional

Published
2019
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25. Assembly of the Entire Carbon Backbone of a Stereoisomer of the Antitumor Marine Natural Product Hemicalide

Author

Lecourt, Camille, primary, Dhambri, Sabrina, additional, Yamani, Khalil, additional, Boissonnat, Guillaume, additional, Specklin, Simon, additional, Fleury, Etienne, additional, Hammad, Karim, additional, Auclair, Eric, additional, Sablé, Serge, additional, Grondin, Antonio, additional, Arimondo, Paola B., additional, Sautel, François, additional, Massiot, Georges, additional, Meyer, Christophe, additional, Cossy, Janine, additional, Sorin, Geoffroy, additional, Lannou, Marie‐Isabelle, additional, and Ardisson, Janick, additional

Published
2019
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31. Radio Resource Management Optimization For Next Generation Wireless Networks

Author

Hammad, Karim Ahmed

Subjects
LTE, Ray Tracing, and Energy-Efficient Communications, Delay Jitter, Systems and Communications, C-RAN, QoS, Resource Allocation
Abstract

The prominent versatility of today’s mobile broadband services and the rapid advancements in the cellular phones industry have led to a tremendous expansion in the wireless market volume. Despite the continuous progress in the radio-access technologies to cope with that expansion, many challenges still remain that need to be addressed by both the research and industrial sectors. One of the many remaining challenges is the efficient allocation and management of wireless network resources when using the latest cellular radio technologies (e.g., 4G). The importance of the problem stems from the scarcity of the wireless spectral resources, the large number of users sharing these resources, the dynamic behavior of generated traffic, and the stochastic nature of wireless channels. These limitations are further tightened as the provider’s commitment to high quality-of-service (QoS) levels especially data rate, delay and delay jitter besides the system’s spectral and energy efficiencies. In this dissertation, we strive to solve this problem by presenting novel cross-layer resource allocation schemes to address the efficient utilization of available resources versus QoS challenges using various optimization techniques. The main objective of this dissertation is to propose a new predictive resource allocation methodology using an agile ray tracing (RT) channel prediction approach. It is divided into two parts. The first part deals with the theoretical and implementational aspects of the ray tracing prediction model, and its validation. In the second part, a novel RT-based scheduling system within the evolving cloud radio access network (C-RAN) architecture is proposed. The impact of the proposed model on addressing the long term evolution (LTE) network limitations is then rigorously investigated in the form of optimization problems. The main contributions of this dissertation encompass the design of several heuristic solutions based on our novel RT-based scheduling model, developed to meet the aforementioned objectives while considering the co-existing limitations in the context of LTE networks. Both analytical and numerical methods are used within this thesis framework. Theoretical results are validated with numerical simulations. The obtained results demonstrate the effectiveness of our proposed solutions to meet the objectives subject to limitations and constraints compared to other published works.

Published
2016

38. Detection, Isolation, and 1H NMR Quantitation of the Nitrile Glycoside Sarmentosin from a Bryophyllum pinnatumHydro-Ethanolic Extract

Author

Fernandes, Júlia Morais, Termentzi, Aikaterini, Mandova, Tsvetelina, Hammad, Karim, Machera, Kyriaki, Magiatis, Prokopios, Michel, Sylvie, Zucolotto, Silvana M., and Grougnet, Raphaël

Abstract

Bryophyllum pinnatum(Lam) Pers. (Crassulaceae) is widely used in folk medicine as leaf juice, aqueous, or hydro-ethanolic extracts. It is also listed as a medicinal plant in several countries such as France and Brazil. The main reported constituents are flavone glycosides, especially those with the rare 3-O-α-l-arabinopyranosyl-(1 → 2)-α-l-rhamnopyranoside moiety. Despite several phytochemical screenings indicating the presence of cyanide derivatives or alkaloids, there are no reports of nitrogenous metabolite characterization from this plant species. Nevertheless, the occurrence and the type of such compounds are of particular interest, as they may account for some of the numerous biological activities and ethnomedicinal uses described for B. pinnatumand could be regarded as chemical/taxonomic markers. Consequently, a hydro-ethanolic extract of B. pinnatumwas investigated by using UHPLC–HRMS/MS and the nitrile glucoside sarmentosin was detected for the first time within the genus Bryophyllum/Kalanchoe. Considering the wide use of B. pinnatumand its closely related species for health purposes, the target metabolite was isolated by a combination of centrifugal partition chromatography in elution/extrusion mode and MPLC in order to confirm its structure. A linear, selective, precise, fast, and reliable 1H NMR quantitation method was then developed and validated and may become a tool for easy quality assessment of the plant species. The amount of sarmentosin was determined as 2.07% of the examined sample. Sarmentosin was also detected in Kalanchoe laciniata,confirming the occurrence of this compound within the genus.

Published
2021
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39. Chronic Viral Infection Promotes Efficient Germinal Center B Cell Responses

Author

Fallet, Bénédict, Hao, Yi, Florova, Marianna, Cornille, Karen, De los Aires, Alba V., Girelli Zubani, Giulia, Ertuna, Yusuf I., Greiff, Victor, Menzel, Ulrike, Hammad, Karim, Merkler, Doron, Reddy, Sai T., Weill, Jean-Claude, Reynaud, Claude-Agnès, and Pinschewer, Daniel D.

Subjects
3. Good health
Abstract

Persistent viral infections subvert key elements of adaptive immunity. To compare germinal center (GC) B cell responses in chronic and acute lymphocytic choriomeningitis virus infection, we exploit activation-induced deaminase (AID) fate-reporter mice and perform adoptive B cell transfer experiments. Chronic infection yields GC B cell responses of higher cellularity than acute infections do, higher memory B cell and antibody secreting cell output for longer periods of time, a better representation of the late B cell repertoire in serum immunoglobulin, and higher titers of protective neutralizing antibodies. GC B cells of chronically infected mice are similarly hypermutated as those emerging from acute infection. They efficiently adapt to viral escape variants and even in hypermutation-impaired AID mutant mice, chronic infection selects for GC B cells with hypermutated B cell receptors (BCRs) and neutralizing antibody formation. These findings demonstrate that, unlike for CD8+ T cells, chronic viral infection drives a functional, productive, and protective GC B cell response., Cell Reports, 30 (4), ISSN:2666-3864, ISSN:2211-1247

40. Detection, Isolation, and 1 H NMR Quantitation of the Nitrile Glycoside Sarmentosin from a Bryophyllum pinnatum Hydro-Ethanolic Extract.

Author

Fernandes JM, Termentzi A, Mandova T, Hammad K, Machera K, Magiatis P, Michel S, Zucolotto SM, and Grougnet R

Subjects
Brazil, France, Glycosides, Nitriles, Plant Extracts, Plant Leaves, Proton Magnetic Resonance Spectroscopy, Kalanchoe
Abstract

Bryophyllum pinnatum (Lam) Pers. (Crassulaceae) is widely used in folk medicine as leaf juice, aqueous, or hydro-ethanolic extracts. It is also listed as a medicinal plant in several countries such as France and Brazil. The main reported constituents are flavone glycosides, especially those with the rare 3-O-α-l-arabinopyranosyl-(1 → 2)-α-l-rhamnopyranoside moiety. Despite several phytochemical screenings indicating the presence of cyanide derivatives or alkaloids, there are no reports of nitrogenous metabolite characterization from this plant species. Nevertheless, the occurrence and the type of such compounds are of particular interest, as they may account for some of the numerous biological activities and ethnomedicinal uses described for B. pinnatum and could be regarded as chemical/taxonomic markers. Consequently, a hydro-ethanolic extract of B. pinnatum was investigated by using UHPLC-HRMS/MS and the nitrile glucoside sarmentosin was detected for the first time within the genus Bryophyllum/Kalanchoe . Considering the wide use of B. pinnatum and its closely related species for health purposes, the target metabolite was isolated by a combination of centrifugal partition chromatography in elution/extrusion mode and MPLC in order to confirm its structure. A linear, selective, precise, fast, and reliable 1 H NMR quantitation method was then developed and validated and may become a tool for easy quality assessment of the plant species. The amount of sarmentosin was determined as 2.07% of the examined sample. Sarmentosin was also detected in Kalanchoe laciniata, confirming the occurrence of this compound within the genus.

Published
2021
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