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502 results on '"Rizk, N."'

1. Adiponectin Ameliorates Hyperglycemia-Induced Retinal Endothelial Dysfunction, Highlighting Pathways, Regulators, and Networks

Author

Bushra S, Al-Sadeq DW, Bari R, Sahara A, Fadel A, and Rizk N

Subjects
adiponectin, hyperglycemia, human microvascular retinal endothelial cells, diabetic retinopathy, bioinformatic analysis., Pathology, RB1-214, Therapeutics. Pharmacology, RM1-950
Abstract

Sumbul Bushra,1,* Duaa W Al-Sadeq,1,* Redwana Bari,1 Afifah Sahara,1 Amina Fadel,1 Nasser Rizk1,2 1Department of Biomedical Sciences, College of Health Sciences, QU-Health, Qatar University, Doha, Qatar; 2Biomedical Research Center (BRC), Qatar University, Doha, Qatar*These authors contributed equally to this workCorrespondence: Nasser Rizk, Department of Biomedical Sciences, College of Health Sciences, QU-Health, Qatar University, P.O. Box 2713, Doha, Qatar, Tel +974-4403-4786, Email nassrizk@qu.edu.qaBackground: The pathophysiology of diabetic retinopathy (DR) is multifaced. A low level of circulating adiponectin (APN) in type 2 diabetes is associated with microvasculature complications, and its role in the evolution of DR is complex.Aim: This study is designed to explore the potential impact of APN in the pathogenesis of DR, linking the changes in cellular and biological processes with the pathways, networks, and regulators involved in its actions.Methods: Human microvascular retinal endothelial cells (HMRECs) were exposed to 30mM glucose (HG) and treated with globular adiponectin (30μg/mL) for 24 hours. The cells were evaluated for reactive oxidative stress (ROS) and apoptosis. RT-PCR profile arrays were utilized to evaluate the profile of genes involved in endothelial functions, angiogenesis, extracellular matrix, and adhesion molecules for hyperglycemic HMRECs treated with adiponectin. In addition, the barrier function, leukocyte migration, and angiogenesis were evaluated. The differential expressed genes (DEGs) were outlined, and bioinformatic analysis was applied.Results: Adiponectin suppresses ROS production and apoptosis in HMRECs under HG conditions. Adiponectin improved migration and barrier functions in hyperglycemic cells. The bioinformatic analysis highlighted that the signaling pathways of integrin, HMGB1, and p38 AMPK, are mainly involved in the actions of APN on HMRECs. APN significantly affects molecular functions, including the adhesion of cells, chemotaxis, migration of WBCs, and angiogenesis. STAT3, NFKB, IKBKB, and mir-8 are the top upstream regulators, which affect the expressions of the genes of the data set, while TNF and TGFB1 are the top regulators.Conclusion: Adiponectin significantly counteracts hyperglycemia at various cellular and molecular levels, reducing its impact on the pathophysiological progression towards DR in vitro using HMRECs. Adiponectin ameliorates inflammatory response, oxidative stress, and endothelial barrier dysfunction using a causal network of NFBk complex, TNF, and HMGB1 and integrin pathways.Keywords: adiponectin, hyperglycemia, human microvascular retinal endothelial cells, diabetic retinopathy, bioinformatic analysis

Published
2022

8. A pilot study on metabolic syndrome and its associated features among Qatari schoolchildren

Author

Rizk N, Amin M, and Yousef M

Subjects
Medicine (General), R5-920
Abstract

Nasser Rizk, Mona Amin, Mervat YousefHealth Sciences Department, University of Qatar, Doha, QatarAim: This pilot study aimed to evaluate the individual features of the metabolic syndrome (MeS) and its frequency in Qatari schoolchildren aged 6–12 years.Background: MeS has a strong future risk for development of diabetes and cardiovascular diseases. Childhood obesity is increasing the likelihood of MeS in children.Methods: The associated features of MeS were assessed in 67 children. They were recruited from the outpatient pediatric clinic at Hamad Medical Corporation, Qatar. Height, weight, and waist circumference were measured and body mass index was calculated for each child. Fasting blood glucose, total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol and triglycerides (TG) were measured. MeS was defined according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP-III) which was modified by Cook with adjustment for fasting glucose to ≥5.6 mM according to recommendations from the American Diabetes Association.Results: The overall prevalence of MeS according to NCEP-III criteria was 3.0% in children aged 6–12 years. Overweight and obesity was 31.3% in children aged 6–12 years, according to the International Obesity Task Force criteria. The prevalence of MeS was 9.5% in overweight and obese subjects. Increased TG levels represented the most frequent abnormality (28.4%) in metabolic syndrome features in all subjects, followed by HDL-C (19.4%) in all subjects.Conclusion: Increased TG levels and low HDL-C were the most frequent components of this syndrome. This study showed a significant prevalence of MeS and associated features among overweight and obese children. The overall prevalence of MeS in Qatari children is in accordance with data from several other countries.Keywords: metabolic syndrome, National Cholesterol Education Program Adult Treatment Panel III, schoolchildren, Qatar

Published
2011

9. A multinational Delphi consensus to end the COVID-19 public health threat

Author

Lazarus, J. V., Romero, D., Kopka, C. J., Karim, S. A., Abu-Raddad, L. J., Almeida, G., Baptista-Leite, R., Barocas, J. A., Barreto, M. L., Bar-Yam, Y., Bassat, Q., Batista, C., Bazilian, M., Chiou, S. -T., del Rio, C., Dore, G. J., Gao, G. F., Gostin, L. O., Hellard, M., Jimenez, J. L., Kang, G., Lee, N., Maticic, M., Mckee, M., Nsanzimana, S., Oliu-Barton, M., Pradelski, B., Pyzik, O., Rabin, K., Raina, S., Rashid, S. F., Rathe, M., Saenz, R., Singh, S., Trock-Hempler, M., Villapol, S., Yap, P., Binagwaho, A., Kamarulzaman, A., El-Mohandes, A., Barreto, M., Abdulla, S., Addleman, S., Aghayeva, G., Agius, R., Ahmed, M., Ramy, M. A., Aide, P., Aleman, S., Alfred, J. -P., Ali, S., Aliaga, J., Aloudat, T., Alqahtani, S. A., Al-Salman, J., Amuasi, J. H., Agrawal, A., Anwar, W., Araujo-Jorge, T., Artaza, O., Asadi, L., Awuku, Y., Baker, M., Barberia, L., Bascolo, E., Belcher, P., Bell, L., Benzaken, A., Bergholtz, E., Bhadelia, N., Bhan, A., Bilodeau, S., Bitran, R., Bluyssen, P., Bosman, A., Bozza, F. A., Brinkmann, M. M., Brown, A., Mellado, B., Bukusi, E., Bullen, C., Buonanno, G., Burgess, R., Butler, M., Byakika-Kibwika, P., Cabieses, B., Carlsson, G., Cascini, Fidelia, Chabala, C., Chakroun, M., Cheng, K. K., Chetty, A., Chumachenko, D., Consalves, G., Conway Morris, A., Cordie, A., Corrah, T., Crabtree-Ramirez, B., Dashdorj, N., Davidovitch, N., de Souza, L. E., Dhariwal, A. C., Druica, E., Ergonul, O., Erondu, N. A., Essar, M. Y., Ewing, A., Fanjul, G., Feierstein, D., Feigl-Ding, E., Figueroa, R., Figueroa, J. P., Fisher, D., Flores, W., Forero-Pena, D. A., Frumkin, H., Gamkrelidze, A., Gandhi, M., Garcia, P., Garcia-Basteiro, A. L., Garcia-Sastre, A., Garg, S., Gbeasor-Komlanvi, F. A., Gershenson, C., Gilada, I., Giovanella, L., Gonzalez, M., Green, M. S., Greenhalgh, T., Griffin, P., Griffin, S., Grinsztejn, B., Anand, T., Guerra, G., Guinto, R., Gujski, M., Guner, R., Hamdy, A., Hancean, M. -G., Haniffa, A., Hartigan-Go, K. Y., Hassan, H. K., Hay, S. I., Heino, M. T. J., Hel, Z., Hotez, P., Hu, J., Hukic, M., Ijsselmuiden, C., Iroko, D., Iskarous, M., Izugbara, C., Jacobs, C., Jadad, A. R., Jehan, F., Jordan, A., Jroundi, I., Kain, K., Kamberi, F., Karamov, E., Karan, A., Katz, R., Katzourakis, A., Kazembe, A., Khamis, F., Khamzayev, K., Khanyola, J., Khunti, K., Kiguli-Malwadde, E., Kim, W. J., Kirenga, B. J., Klimovsky, D., Kmush, B. L., Knaul, F., Kogevinas, M., Kristensen, F., Kumar, D., Kumar, R., Kvalsvig, A., Lacerda, M. V., Lal, A., Lawton, T., Lemery, J., Leonardi, A. J., Li, Y., Lottvall, J., Lounis, M., Maceira, D., Macintyre, C. R., Madani, A., Magiorkinis, G., Malekzadeh, R., Choisy, M., Marcelin, J. R., Marks, G. B., Marr, L., Marrazzo, J., Martina, A., Martin-Moreno, J. M., Mateos, C., Mayxay, M., Mazarati, J. B., Mboup, S., Mcdonald, J., Mcmillan, F., Mechili, E., Medici, A., Davis, S. L. M., Meier, P., Memish, Z. A., Menon, J., Menon, P., Mesiano-Crookston, J., Michie, S., Mikolasevic, I., Milicevic, O., Mishra, A. K., Mohamed, R., Mokdad, A. H., Monroy-Valle, M., Morawska, L., Moschos, S. A., Motawea, K., Mousavi, S. H., Mumtaz, G., Munene, P. K., Munoz Almagro, C., Muriuki, J., Muyingo, S., Naniche, D., Naylor, C. D., Ndembi, N., Nemec, J., Nesteruk, I., Ngaruiya, C., Nguyen, H., Nikolova, D., Nitzan, D., Norheim, O., Noushad, M., Ntoumi, F., Nyborg, G. A., Ochodo, E., Odabasi, Z., Okwen, M. P., Olivia, K., Ong, D. S. Y., Opara, I., Orozco, M., Oshitani, H., Pagel, C., Pai, M., Palsdottir, B., Papatheodoridis, G., Paraskevis, D., Leigh, J. P., Pecoul, B., Peichl, A., Perez-Then, E., Duc, P. P., Philippe, C., Pineda Rojas, A., Pladsen, C., Pozniak, A., Quiroga, R., Qureshi, H., Rampal, S., Ranney, M., Rathe, L., Ratzan, S., Raventos, H., Rees, H., Reis, R., Ricciardi, Walter, Rizk, N., Robalo, M., Robertson, E., Robinson, L., Rokx, C., Ros, T., Rottingen, J. -A., Rubin, M., Ruxrungtam, K., Sadirova, S., Saha, S., Salgado, N., Sanchez, L., Sangaramoorthy, T., Santamaria-Ulloa, C., Santos, R., Sawaf, B., Schneider, M. F., Schooley, R. T., Sener, A., Sepulveda, J., Shah, J., Shibani, M., Shoib, S., Sikazwe, I., Simaitis, A., Gill, A. S., Skhvitaridze, N., Sokolovic, M., Solomon, R., Solorzano, X., Springer, S. A., Srol, J., Staines, A., Stelfox, H. T., Strathdee, S., Sulaiman, L. H., Sutton, B., Svanaes, D., Swed, S., Sypsa, V., Sorensen, K., Tajudeen, R., Tan, A., Tang, J., Tanner, M., Sethi, T., Temmerman, M., Than, K. K., Tinto, H., Tometissi, S. P., Torres, I., Tshering, K. P., Tsiodras, S., Tsofa, B., Vahlne, A., Vargas, J. R., Bernal, I. D. V., Ventura, D., Vilasanjuan, R., Vipond, J., Wamala-Andersson, S., Wargocki, P., West, R., Weyand, A., White, T. M., Wolff, G., Yao, M., Yates, C. A., Yeboah, G., Yee-Sin, L., Yi, S., Teo, Y. -Y., Yong, P., Zamora-Mesia, V., Ovrehus, A., Cascini F. (ORCID:0000-0001-6499-0734), Ricciardi W. (ORCID:0000-0002-5655-688X), Lazarus, J. V., Romero, D., Kopka, C. J., Karim, S. A., Abu-Raddad, L. J., Almeida, G., Baptista-Leite, R., Barocas, J. A., Barreto, M. L., Bar-Yam, Y., Bassat, Q., Batista, C., Bazilian, M., Chiou, S. -T., del Rio, C., Dore, G. J., Gao, G. F., Gostin, L. O., Hellard, M., Jimenez, J. L., Kang, G., Lee, N., Maticic, M., Mckee, M., Nsanzimana, S., Oliu-Barton, M., Pradelski, B., Pyzik, O., Rabin, K., Raina, S., Rashid, S. F., Rathe, M., Saenz, R., Singh, S., Trock-Hempler, M., Villapol, S., Yap, P., Binagwaho, A., Kamarulzaman, A., El-Mohandes, A., Barreto, M., Abdulla, S., Addleman, S., Aghayeva, G., Agius, R., Ahmed, M., Ramy, M. A., Aide, P., Aleman, S., Alfred, J. -P., Ali, S., Aliaga, J., Aloudat, T., Alqahtani, S. A., Al-Salman, J., Amuasi, J. H., Agrawal, A., Anwar, W., Araujo-Jorge, T., Artaza, O., Asadi, L., Awuku, Y., Baker, M., Barberia, L., Bascolo, E., Belcher, P., Bell, L., Benzaken, A., Bergholtz, E., Bhadelia, N., Bhan, A., Bilodeau, S., Bitran, R., Bluyssen, P., Bosman, A., Bozza, F. A., Brinkmann, M. M., Brown, A., Mellado, B., Bukusi, E., Bullen, C., Buonanno, G., Burgess, R., Butler, M., Byakika-Kibwika, P., Cabieses, B., Carlsson, G., Cascini, Fidelia, Chabala, C., Chakroun, M., Cheng, K. K., Chetty, A., Chumachenko, D., Consalves, G., Conway Morris, A., Cordie, A., Corrah, T., Crabtree-Ramirez, B., Dashdorj, N., Davidovitch, N., de Souza, L. E., Dhariwal, A. C., Druica, E., Ergonul, O., Erondu, N. A., Essar, M. Y., Ewing, A., Fanjul, G., Feierstein, D., Feigl-Ding, E., Figueroa, R., Figueroa, J. P., Fisher, D., Flores, W., Forero-Pena, D. A., Frumkin, H., Gamkrelidze, A., Gandhi, M., Garcia, P., Garcia-Basteiro, A. L., Garcia-Sastre, A., Garg, S., Gbeasor-Komlanvi, F. A., Gershenson, C., Gilada, I., Giovanella, L., Gonzalez, M., Green, M. S., Greenhalgh, T., Griffin, P., Griffin, S., Grinsztejn, B., Anand, T., Guerra, G., Guinto, R., Gujski, M., Guner, R., Hamdy, A., Hancean, M. -G., Haniffa, A., Hartigan-Go, K. Y., Hassan, H. K., Hay, S. I., Heino, M. T. J., Hel, Z., Hotez, P., Hu, J., Hukic, M., Ijsselmuiden, C., Iroko, D., Iskarous, M., Izugbara, C., Jacobs, C., Jadad, A. R., Jehan, F., Jordan, A., Jroundi, I., Kain, K., Kamberi, F., Karamov, E., Karan, A., Katz, R., Katzourakis, A., Kazembe, A., Khamis, F., Khamzayev, K., Khanyola, J., Khunti, K., Kiguli-Malwadde, E., Kim, W. J., Kirenga, B. J., Klimovsky, D., Kmush, B. L., Knaul, F., Kogevinas, M., Kristensen, F., Kumar, D., Kumar, R., Kvalsvig, A., Lacerda, M. V., Lal, A., Lawton, T., Lemery, J., Leonardi, A. J., Li, Y., Lottvall, J., Lounis, M., Maceira, D., Macintyre, C. R., Madani, A., Magiorkinis, G., Malekzadeh, R., Choisy, M., Marcelin, J. R., Marks, G. B., Marr, L., Marrazzo, J., Martina, A., Martin-Moreno, J. M., Mateos, C., Mayxay, M., Mazarati, J. B., Mboup, S., Mcdonald, J., Mcmillan, F., Mechili, E., Medici, A., Davis, S. L. M., Meier, P., Memish, Z. A., Menon, J., Menon, P., Mesiano-Crookston, J., Michie, S., Mikolasevic, I., Milicevic, O., Mishra, A. K., Mohamed, R., Mokdad, A. H., Monroy-Valle, M., Morawska, L., Moschos, S. A., Motawea, K., Mousavi, S. H., Mumtaz, G., Munene, P. K., Munoz Almagro, C., Muriuki, J., Muyingo, S., Naniche, D., Naylor, C. D., Ndembi, N., Nemec, J., Nesteruk, I., Ngaruiya, C., Nguyen, H., Nikolova, D., Nitzan, D., Norheim, O., Noushad, M., Ntoumi, F., Nyborg, G. A., Ochodo, E., Odabasi, Z., Okwen, M. P., Olivia, K., Ong, D. S. Y., Opara, I., Orozco, M., Oshitani, H., Pagel, C., Pai, M., Palsdottir, B., Papatheodoridis, G., Paraskevis, D., Leigh, J. P., Pecoul, B., Peichl, A., Perez-Then, E., Duc, P. P., Philippe, C., Pineda Rojas, A., Pladsen, C., Pozniak, A., Quiroga, R., Qureshi, H., Rampal, S., Ranney, M., Rathe, L., Ratzan, S., Raventos, H., Rees, H., Reis, R., Ricciardi, Walter, Rizk, N., Robalo, M., Robertson, E., Robinson, L., Rokx, C., Ros, T., Rottingen, J. -A., Rubin, M., Ruxrungtam, K., Sadirova, S., Saha, S., Salgado, N., Sanchez, L., Sangaramoorthy, T., Santamaria-Ulloa, C., Santos, R., Sawaf, B., Schneider, M. F., Schooley, R. T., Sener, A., Sepulveda, J., Shah, J., Shibani, M., Shoib, S., Sikazwe, I., Simaitis, A., Gill, A. S., Skhvitaridze, N., Sokolovic, M., Solomon, R., Solorzano, X., Springer, S. A., Srol, J., Staines, A., Stelfox, H. T., Strathdee, S., Sulaiman, L. H., Sutton, B., Svanaes, D., Swed, S., Sypsa, V., Sorensen, K., Tajudeen, R., Tan, A., Tang, J., Tanner, M., Sethi, T., Temmerman, M., Than, K. K., Tinto, H., Tometissi, S. P., Torres, I., Tshering, K. P., Tsiodras, S., Tsofa, B., Vahlne, A., Vargas, J. R., Bernal, I. D. V., Ventura, D., Vilasanjuan, R., Vipond, J., Wamala-Andersson, S., Wargocki, P., West, R., Weyand, A., White, T. M., Wolff, G., Yao, M., Yates, C. A., Yeboah, G., Yee-Sin, L., Yi, S., Teo, Y. -Y., Yong, P., Zamora-Mesia, V., Ovrehus, A., Cascini F. (ORCID:0000-0001-6499-0734), and Ricciardi W. (ORCID:0000-0002-5655-688X)

Abstract

Despite notable scientific and medical advances, broader political, socioeconomic and behavioural factors continue to undercut the response to the COVID-19 pandemic1,2. Here we convened, as part of this Delphi study, a diverse, multidisciplinary panel of 386 academic, health, non-governmental organization, government and other experts in COVID-19 response from 112 countries and territories to recommend specific actions to end this persistent global threat to public health. The panel developed a set of 41 consensus statements and 57 recommendations to governments, health systems, industry and other key stakeholders across six domains: communication; health systems; vaccination; prevention; treatment and care; and inequities. In the wake of nearly three years of fragmented global and national responses, it is instructive to note that three of the highest-ranked recommendations call for the adoption of whole-of-society and whole-of-government approaches1, while maintaining proven prevention measures using a vaccines-plus approach2 that employs a range of public health and financial support measures to complement vaccination. Other recommendations with at least 99% combined agreement advise governments and other stakeholders to improve communication, rebuild public trust and engage communities3 in the management of pandemic responses. The findings of the study, which have been further endorsed by 184 organizations globally, include points of unanimous agreement, as well as six recommendations with >5% disagreement, that provide health and social policy actions to address inadequacies in the pandemic response and help to bring this public health threat to an end.

Published
2022

12. Synchronized production-distribution planning in a single-plant multi-destination network

Author

Rizk, N., Martel, A., and D'Amours, S.

Subjects
Linear programming -- Analysis, Lead time -- Analysis, Business, Business, general
Abstract

This paper examines the flow synchronization problem between a manufacturing location and multiple destinations. Multiple products can be shipped from the manufacturing location to different locations via multiple transportation modes. These transportation modes may have different transportation lead times. The transportation costs structure of the different transportation modes offer economies of scale and can be represented by general piecewise linear functions. The production system at the manufacturing location is a serial process with a bottleneck stage. At the bottleneck stage, a predetermined production sequence must be maintained as is the case in some process-based industries. We propose a tight mixed integer programming model for integrated planning of production and distribution in the network. We show that by adding simple valid inequalities and special 0-1 variables, major computational improvements can be achieved when solving this problem with commercial solvers such as Cplex. We also propose a sequential solution approach, based on the independent, but synchronized, solutions of the production and distribution sub-problems. Finally, the solution methods proposed are tested experimentally for realistic problems and the advantage of integrated planning over independent but synchronized planning is assessed. Keywords: production--listribution synchronization: multi-item lot-sizing; dynamic demand; piecewise linear costs; mixed integer programming; valid inequalities

Published
2008

14. Antimicrobial stewardship in the ICU in COVID-19 times: the known unknowns

Author

Schouten, J.A., Waele, J. De, Lanckohr, C., Koulenti, D., Haddad, N., Rizk, N., Sjövall, F., Kanj, S.S., Schouten, J.A., Waele, J. De, Lanckohr, C., Koulenti, D., Haddad, N., Rizk, N., Sjövall, F., and Kanj, S.S.

Abstract

Item does not contain fulltext, Since the start of the COVID-19 pandemic, there has been concern about the concomitant rise of antimicrobial resistance. While bacterial co-infections seem rare in COVID-19 patients admitted to hospital wards and intensive care units (ICUs), an increase in empirical antibiotic use has been described. In the ICU setting, where antibiotics are already abundantly-and often inappropriately-prescribed, the need for an ICU-specific antimicrobial stewardship programme is widely advocated. Apart from essentially warning against the use of antibacterial drugs for the treatment of a viral infection, other aspects of ICU antimicrobial stewardship need to be considered in view of the clinical course and characteristics of COVID-19. First, the distinction between infectious and non-infectious (inflammatory) causes of respiratory deterioration during an ICU stay is difficult, and the much-debated relevance of fungal and viral co-infections adds to the complexity of empirical antimicrobial prescribing. Biomarkers such as procalcitonin for the decision to start antibacterial therapy for ICU nosocomial infections seem to be more promising in COVID-19 than non-COVID-19 patients. In COVID-19 patients, cytomegalovirus reactivation is an important factor to consider when assessing patients infected with SARS-CoV-2 as it may have a role in modulating the patient immune response. The diagnosis of COVID-19-associated invasive aspergillosis is challenging because of the lack of sensitivity and specificity of the available tests. Furthermore, altered pharmacokinetic/pharmacodynamic properties need to be taken into account when prescribing antimicrobial therapy. Future research should now further explore the 'known unknowns', ideally with robust prospective study designs.

Published
2021

15. Consensus statement on the role of health systems in advancing the long-term well-being of people living with HIV

Author

Lazarus, JV, Safreed-Harmon, K, Kamarulzaman, A, Anderson, J, Leite, RB, Behrens, G, Bekker, L-G, Bhagani, S, Brown, D, Brown, G, Buchbinder, S, Caceres, C, Cahn, PE, Carrieri, P, Caswell, G, Cooke, GS, Monforte, AD, Dedes, N, del Amo, J, Elliott, R, El-Sadr, WM, Fuster-Ruiz de Apodaca, MJ, Guaraldi, G, Hallett, T, Harding, R, Hellard, M, Jaffar, S, Kall, M, Klein, M, Lewin, SR, Mayer, K, Perez-Molina, JA, Moraa, D, Naniche, D, Nash, D, Noori, T, Pozniak, A, Rajasuriar, R, Reiss, P, Rizk, N, Rockstroh, J, Romero, D, Sabin, C, Serwadda, D, Waters, L, Lazarus, JV, Safreed-Harmon, K, Kamarulzaman, A, Anderson, J, Leite, RB, Behrens, G, Bekker, L-G, Bhagani, S, Brown, D, Brown, G, Buchbinder, S, Caceres, C, Cahn, PE, Carrieri, P, Caswell, G, Cooke, GS, Monforte, AD, Dedes, N, del Amo, J, Elliott, R, El-Sadr, WM, Fuster-Ruiz de Apodaca, MJ, Guaraldi, G, Hallett, T, Harding, R, Hellard, M, Jaffar, S, Kall, M, Klein, M, Lewin, SR, Mayer, K, Perez-Molina, JA, Moraa, D, Naniche, D, Nash, D, Noori, T, Pozniak, A, Rajasuriar, R, Reiss, P, Rizk, N, Rockstroh, J, Romero, D, Sabin, C, Serwadda, D, and Waters, L

Abstract

Health systems have improved their abilities to identify, diagnose, treat and, increasingly, achieve viral suppression among people living with HIV (PLHIV). Despite these advances, a higher burden of multimorbidity and poorer health-related quality of life are reported by many PLHIV in comparison to people without HIV. Stigma and discrimination further exacerbate these poor outcomes. A global multidisciplinary group of HIV experts developed a consensus statement identifying key issues that health systems must address in order to move beyond the HIV field's longtime emphasis on viral suppression to instead deliver integrated, person-centered healthcare for PLHIV throughout their lives.

Published
2021

19. Studies on liquid sheet disintegration in airblast atomizers

Author

Rizk, N. K. and Lifebvre, A. H.

Subjects
621
Abstract

The work in this thesis has been devoted to studying the influence of liquid film thickness on the characteristics of airblast atomizers. The research was carried out using two special atomizers that were both designed to produce flat liquid sheets which were atomized by high velocity air streams acting on both sides of the shoot. The liquid was injected through sintered plates in the first design, while the film issued from a variable gap, slot in the second design.

Published
1976

36. The Effectiveness and Cost-Effectiveness of Screening for HIV in Migrants in the EU/EEA: A Systematic Review

Author

Pottie, K, Lotfi, T, Kilzar, L, Howeiss, P, Rizk, N, Akl, EA, Dias, S, Biggs, B-A, Christensen, R, Rahman, P, Magwood, O, Tran, A, Rowbotham, N, Pharris, A, Noori, T, Pareek, M, Morton, R, Pottie, K, Lotfi, T, Kilzar, L, Howeiss, P, Rizk, N, Akl, EA, Dias, S, Biggs, B-A, Christensen, R, Rahman, P, Magwood, O, Tran, A, Rowbotham, N, Pharris, A, Noori, T, Pareek, M, and Morton, R

Abstract

Migrants, defined as individuals who move from their country of origin to another, account for 40% of newly-diagnosed cases of human immunodeficiency virus (HIV) in the European Union/European Economic Area (EU/EEA). Populations at high risk for HIV include migrants, from countries or living in neighbourhoods where HIV is prevalent, and those participating in high risk behaviour. These migrants are at risk of low CD4 counts at diagnosis, increased morbidity, mortality, and onward transmission. The aim of this systematic review is to evaluate the effectiveness and cost-effectiveness of HIV testing strategies in migrant populations and to estimate their effect on testing uptake, mortality, and resource requirements. Following a systematic overview, we included four systematic reviews on the effectiveness of strategies in non-migrant populations and inferred their effect on migrant populations, as well as eight individual studies on cost-effectiveness/resource requirements. We assessed the certainty of our results using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. The systematic reviews reported that HIV tests are highly accurate (rapid test >90% sensitivity, Western blot and ELISA >99% sensitivity). A meta-analysis showed that rapid testing approaches improve the access and uptake of testing (risk ratio = 2.95, 95% CI: 1.69 to 5.16), and were associated with a lower incidence of HIV in the middle-aged women subgroup among marginalised populations at a high risk of HIV exposure and HIV related stigma. Economic evidence on rapid counselling and testing identified strategic advantages with rapid tests. In conclusion, community-based rapid testing programmes may have the potential to improve uptake of HIV testing among migrant populations across a range of EU/EEA settings.

Published
2018

38. Characterization of chemical and biological clogging and their interactions within a micro-irrigation system in the context of the reuse of treated effluents in irrigation

Author

Rizk, N., Gestion de l'Eau, Acteurs, Usages (UMR G-EAU), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and Doctorat Génie des Procédés, Université d'Aix-Marseille

Subjects
CHEMICAL PRECIPITATION, SHEAR STRESS, PHREEQC, [SDE]Environmental Sciences, thesis, thèse
Abstract

In the context of global change reaching the general hydro-ecological and biodemographic parameters, micro-irrigation used in agriculture with treated wastewater is a promising approach to reduce water expenditure. However, the clogging of micro-irrigation systems constitutes a constraint on the use of these waters containing micro-organisms, nutrients and dissolved salts. These contaminants can lead to chemical precipitation with the development of biofilms that degrade the performance of irrigation systems. Consequently, the objectives of this study can be defined as follows: (i) to characterize the precipitation of dissolved salts due to variations in operating conditions along the micro-irrigation systems, (ii) to study the development of biofilms through the use of treated wastewater under different hydrodynamic conditions, and (iii) to analyze some interactions between chemical precipitation and the development of biofilm. First, a study was implemented to identify the impact of the parameters that influence chemical precipitation. These parameters are temperature, pH and partial pressure of CO2. This study permits the quantification of the increase in the mass of the precipitate produced in the form of calcite (calcium carbonate) as a function of the increase in pH and temperature. The experimental results allowed validation and calibration of the modeling of the precipitation under PHREEQC's software. This numerical model allows prediction and quantification of chemical precipitation for a given water quality under various operating conditions of pH, temperature and CO2 partial pressure. Experiments were then carried out using an irrigation set-up to study the influence of calcium carbonate on the growth of biofilms in micro-irrigation pipes and drippers (distribution drippers). In parallel, a Taylor-Couette reactor (TCR) was used to study the influence of shear stress on the development of biofilms. Depending on the position in the irrigation system, 3 shear stresses were identified and analyzed. In the pipe, a shear stress of 0.7 Pa was retained and in the drippers the shear stress was between 2.2 and 4.4 Pa. It is observed that the biofilm tends to develop under the highest shear stress. Precipitation of calcium carbonate in the form of calcite was observed in interaction with the growth of the biofilm.; (trad auto)Dans un contexte de changement global atteignant les paramètres hydro-écologiques et biodémographiques généraux, la micro-irrigation utilisée en agriculture avec des eaux usées traitées est une approche prometteuse pour réduire les dépenses en eau. Cependant, l'encrassement des systèmes de micro-irrigation constitue une contrainte à l'utilisation de ces eaux contenant des micro-organismes, des nutriments et des sels dissous. Ces contaminants peuvent conduire à une précipitation chimique avec le développement de biofilms qui dégradent la performance des systèmes d'irrigation. Par conséquent, les objectifs de cette étude peuvent être définis comme suit : (i) caractériser la précipitation des sels dissous due aux variations des conditions de fonctionnement le long des systèmes de micro-irrigation, (ii) étudier le développement de biofilms par l'utilisation d'eaux usées traitées dans différentes conditions hydrodynamiques, et (iii) analyser certaines interactions entre la précipitation chimique et le développement du biofilm. Tout d'abord, une étude a été mise en œuvre pour identifier l'impact des paramètres qui influencent les précipitations chimiques. Ces paramètres sont la température, le pH et la pression partielle de CO2. Cette étude permet de quantifier l'augmentation de la masse du précipité produit sous forme de calcite (carbonate de calcium) en fonction de l'augmentation du pH et de la température. Les résultats expérimentaux ont permis de valider et d'étalonner la modélisation des précipitations à l'aide du logiciel PHREEQC. Ce modèle numérique permet de prédire et de quantifier les précipitations chimiques pour une qualité d'eau donnée dans diverses conditions de fonctionnement (pH, température et pression partielle de CO2). Des expériences ont ensuite été menées à l'aide d'un dispositif d'irrigation pour étudier l'influence du carbonate de calcium sur la croissance des biofilms dans les conduites de micro-irrigation et les goutteurs (goutteurs de distribution). Parallèlement, un réacteur Taylor-Couette (TCR) a été utilisé pour étudier l'influence de la contrainte de cisaillement sur le développement des biofilms. En fonction de la position dans le système d'irrigation, 3 contraintes de cisaillement ont été identifiées et analysées. Dans la conduite, une contrainte de cisaillement de 0,7 Pa a été retenue et dans les goutteurs, la contrainte de cisaillement se situait entre 2,2 et 4,4 Pa. On observe que le biofilm tend à se développer sous la contrainte de cisaillement la plus élevée. Des précipitations de carbonate de calcium sous forme de calcite ont été observées en interaction avec la croissance du biofilm.

Published
2017

39. Caractérisation du colmatage chimique et biologique et leurs interactions au sein d'un dispositif de micro-irrigation dans le contexte de la réutilisation des eaux usées épurées en irrigation

Author

Rizk, N., Gestion de l'Eau, Acteurs, Usages (UMR G-EAU), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Doctorat Génie des Procédés, Université d'Aix-Marseille, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)

Subjects
CHEMICAL PRECIPITATION, SHEAR STRESS, PHREEQC, [SDE]Environmental Sciences, thesis, thèse
Abstract

[Departement_IRSTEA]Eaux [TR1_IRSTEA]GEUSI [Encadrant_IRSTEA]Molle, B. ; Ait Mouheb, N.; In the context of global change reaching the general hydro-ecological and biodemographic parameters, micro-irrigation used in agriculture with treated wastewater is a promising approach to reduce water expenditure. However, the clogging of micro-irrigation systems constitutes a constraint on the use of these waters containing micro-organisms, nutrients and dissolved salts. These contaminants can lead to chemical precipitation with the development of biofilms that degrade the performance of irrigation systems. Consequently, the objectives of this study can be defined as follows: (i) to characterize the precipitation of dissolved salts due to variations in operating conditions along the micro-irrigation systems, (ii) to study the development of biofilms through the use of treated wastewater under different hydrodynamic conditions, and (iii) to analyze some interactions between chemical precipitation and the development of biofilm. First, a study was implemented to identify the impact of the parameters that influence chemical precipitation. These parameters are temperature, pH and partial pressure of CO2. This study permits the quantification of the increase in the mass of the precipitate produced in the form of calcite (calcium carbonate) as a function of the increase in pH and temperature. The experimental results allowed validation and calibration of the modeling of the precipitation under PHREEQC's software. This numerical model allows prediction and quantification of chemical precipitation for a given water quality under various operating conditions of pH, temperature and CO2 partial pressure. Experiments were then carried out using an irrigation set-up to study the influence of calcium carbonate on the growth of biofilms in micro-irrigation pipes and drippers (distribution drippers). In parallel, a Taylor-Couette reactor (TCR) was used to study the influence of shear stress on the development of biofilms. Depending on the position in the irrigation system, 3 shear stresses were identified and analyzed. In the pipe, a shear stress of 0.7 Pa was retained and in the drippers the shear stress was between 2.2 and 4.4 Pa. It is observed that the biofilm tends to develop under the highest shear stress. Precipitation of calcium carbonate in the form of calcite was observed in interaction with the growth of the biofilm.; (trad auto)Dans un contexte de changement global atteignant les paramètres hydro-écologiques et biodémographiques généraux, la micro-irrigation utilisée en agriculture avec des eaux usées traitées est une approche prometteuse pour réduire les dépenses en eau. Cependant, l'encrassement des systèmes de micro-irrigation constitue une contrainte à l'utilisation de ces eaux contenant des micro-organismes, des nutriments et des sels dissous. Ces contaminants peuvent conduire à une précipitation chimique avec le développement de biofilms qui dégradent la performance des systèmes d'irrigation. Par conséquent, les objectifs de cette étude peuvent être définis comme suit : (i) caractériser la précipitation des sels dissous due aux variations des conditions de fonctionnement le long des systèmes de micro-irrigation, (ii) étudier le développement de biofilms par l'utilisation d'eaux usées traitées dans différentes conditions hydrodynamiques, et (iii) analyser certaines interactions entre la précipitation chimique et le développement du biofilm. Tout d'abord, une étude a été mise en uvre pour identifier l'impact des paramètres qui influencent les précipitations chimiques. Ces paramètres sont la température, le pH et la pression partielle de CO2. Cette étude permet de quantifier l'augmentation de la masse du précipité produit sous forme de calcite (carbonate de calcium) en fonction de l'augmentation du pH et de la température. Les résultats expérimentaux ont permis de valider et d'étalonner la modélisation des précipitations à l'aide du logiciel PHREEQC. Ce modèle numérique permet de prédire et de quantifier les précipitations chimiques pour une qualité d'eau donnée dans diverses conditions de fonctionnement (pH, température et pression partielle de CO2). Des expériences ont ensuite été menées à l'aide d'un dispositif d'irrigation pour étudier l'influence du carbonate de calcium sur la croissance des biofilms dans les conduites de micro-irrigation et les goutteurs (goutteurs de distribution). Parallèlement, un réacteur Taylor-Couette (TCR) a été utilisé pour étudier l'influence de la contrainte de cisaillement sur le développement des biofilms. En fonction de la position dans le système d'irrigation, 3 contraintes de cisaillement ont été identifiées et analysées. Dans la conduite, une contrainte de cisaillement de 0,7 Pa a été retenue et dans les goutteurs, la contrainte de cisaillement se situait entre 2,2 et 4,4 Pa. On observe que le biofilm tend à se développer sous la contrainte de cisaillement la plus élevée. Des précipitations de carbonate de calcium sous forme de calcite ont été observées en interaction avec la croissance du biofilm.

Published
2017

41. Characterization of chemical and biological clogging and there interaction in a micro-irrigation system in the context of treated waste water reuse

Author

Rizk, N., MOUHEB, N. AIT, Molle, B., Roche, Nicolas, Gestion de l'Eau, Acteurs, Usages (UMR G-EAU), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Institut de Recherche pour le Développement (IRD)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-AgroParisTech-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, ComputingMilieux_MISCELLANEOUS
Abstract

International audience; no abstract

Published
2015

42. Oxidative Stress Markers In Gestational Diabetes Mellitus

Author

Rizk, N., Sharif, E., Ba'omar, B., and Shublaq, H.

Subjects
Oxidative stress, Gestational diabetes mellitus (GDM)
Abstract

Oxidative stress is typically the result of an imbalance between the reactive oxygen species (ROS) and the antioxidant. The increased production of ROS could lead into some serious physiological problems on the cell, such as: damage of DNA, and peroxidation of lipids and proteins. Normal pregnancy is characterized by an increase of free radical production and lipoperoxidation towards the end of the pregnancy compared with normal non-pregnant women. It is expected that pregnant women with gestational diabetes mellitus (GDM) are highly susceptible of having some imbalance between ROS and antioxidant that could be proved by measuring the level of oxidative stress markers.

Published
2015

44. THE PREVALENCE OF VITAMIN D DEFICIENCY AMONG FEMALES STUDENT AT QATAR UNIVERSITY

Author

Sharif, E.A. and Rizk, N.

Subjects
Vitamin D deficiency, Qatar
Abstract

Background. Vitamin D deficiency is a major worldwide problem with several health consequence such osteoporosis, hyperten- sion, diabetes mellitus, autoimmune diseases and some cancers. The Prevalence of Vitamin D deficiency among female adult students with associated biochemical markers was not measured in the state of Qatar previously. Aim. Measurement of vitamin D level and other clinical parameters related to vitamin D levels. Methods. Randomly selected 71 female students were recruited in Health Science Department of Qatar University for this study. Blood was drawn for measurement of vitamin D, calcium, albumin, alkaline phopsphatase and creatinine. Time of exposure to sun, duration, size of body exposed and dietary intake of vitamin D were quantified based on questioner. Body mass index (BMI) and waist circumference were measured. Results. High percentage of vitamin D deficiency was observed among female students, 97.2% showed severe deficiency and insufficiency in vitamin Dconcentration.100% of the subjects showed a serum calcium level below the optimal level. No significant difference was observed of vitamin D status by nationality. Calcium level and skin color were the significant predictors of vitamin D level in the study while other predictor variables were not significant. Overall, vitamin D deficiency has high prevalence among female student at Qatar University accompanied by hypocalcaemia. Conclusions. Vitamin D deficiency accompanied with hypocalcaemia is highly remarkable among female students (17-30 years old) in Qatar University.

Published
2011

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