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1. Vanadium embedded in monolayer silicene: Energetics and proximity-induced magnetism.

Author

Raji, A. T., Maboe, D. P. A., Benecha, E. M., Dongho-Nguimdo, M., Igumbor, E., and Lombardi, E. B.

Subjects
CURIE temperature, BINDING energy, ELECTRONIC structure, VANADIUM, ATOMS
Abstract

Using the density-functional theory approach, including Hubbard U correction, we investigate the defect structures consisting of vanadium (V) atoms embedded in a monolayer silicene. Specifically, we consider V–V atom pairs in antiferromagnetic (AFM), ferromagnetic (FM), and non-magnetic states, which are embedded in substitutional and interstitial sites. We determine the ground-state structures, formation and binding energies, electronic structures, induced magnetization, as well as the spin-exchange coupling between the V–V pair. For the substitutional vanadium atom pair, the stability of the AFM and FM spin configurations depends on the sublattice sites in which the V atoms are sited. When the V pair is located on a similar sublattice site type, the AFM spin alignment is more energetically favored, whereas when the pair is located in a different sublattice site, the FM interactions are more stable. However, the relative stability of the AFM or FM configurations changes rapidly as the separation between the V pair increases. Regarding the interstitial-hole V–V pair configurations, the most stable structure is when the pair is at the nearest-neighbor hole sites and is in an FM alignment. Also, at larger separations, the AFM or FM hole configurations are approximately degenerate in energy. Furthermore, we elucidate on the Ruderman–Kittel–Kasuya–Yosida, direct-exchange, and the superexchange interaction mechanisms in the vanadium-embedded silicene. In addition, we estimate a Curie temperature (Tc) of up to ∼500 K for a silicene structure containing a V pair in the FM spin alignment. Such a high Tc, in addition to the stability of the material, suggests that vanadium-embedded silicene is a potential candidate material for spintronic device applications. [ABSTRACT FROM AUTHOR]

Published
2024
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13. Fruit, vegetable, and legume intake, and cardiovascular disease and deaths in 18 countries (PURE): a prospective cohort study

Author

Diaz, R, Orlandini, A, Linetsky, B, Toscanelli, S, Casaccia, G, Cuneo, JM Maini, Rahman, O, Yusuf, R, Azad, AK, Rabbani, KA, Cherry, HM, Mannan, A, Hassan, I, Talukdar, AT, Tooheen, RB, Khan, MU, Sintaha, M, Choudhury, T, Haque, R, Parvin, S, Avezum, A, Oliveira, GB, Marcilio, CS, Mattos, AC, Teo, K, Yusuf, S, Dejesus, J, Agapay, D, Tongana, T, Solano, R, Kay, I, Trottier, S, Rimac, J, Elsheikh, W, Heldman, L, Ramezani, E, Dagenais, G, Poirier, P, Turbide, G, Auger, D, De Bluts, A LeBlanc, Proulx, MC, Cayer, M, Bonneville, N, Lear, S, Gasevic, D, Corber, E, de Jong, V, Vukmirovich, I, Wielgosz, A, Fodor, G, Pipe, A, Shane, A, Lanas, F, Seron, P, Martinez, S, Valdebenito, A, Oliveros, M, Wei, Li, Lisheng, Liu, Chunming, Chen, Xingyu, Wang, Wenhua, Zhao, Hongye, Zhang, Xuan, Jia, Bo, Hu, Yi, Sun, Jian, Bo, Xiuwen, Zhao, Xiaohong, Chang, Tao, Chen, Hui, Chen, Qing, Deng, Xiaoru, Cheng, Xinye, He, Jian, Li, Juan, Li, Xu, Liu, Bing, Ren, Wei, Wang, Yang, Wang, Jun, Yang, Yi, Zhai, Manlu, Zhu, Fanghong, Lu, Jianfang, Wu, Yindong, Li, Yan, Hou, Liangqing, Zhang, Baoxia, Guo, Xiaoyang, Liao, Shiying, Zhang, Rongwen, Bian, Xiuzhen, Tian, Dong, Li, Di, Chen, Jianguo, Wu, Yize, Xiao, Tianlu, Liu, Peng, Zhang, Changlin, Dong, Ning, Li, Xiaolan, Ma, Yuqing, Yang, Rensheng, Lei, Minfan, Fu, Jing, He, Yu, Liu, Xiaojie, Xing, Qiang, Zhou, Lopez-Jaramillo, P, Lopez, PA Camacho, Garcia, R, Jurado, LJA, Gómez-Arbeláez, D, Arguello, JF, Dueñas, R, Silva, S, Pradilla, LP, Ramirez, F, Molina, DI, Cure-Cure, C, Perez, M, Hernandez, E, Arcos, E, Fernandez, S, Narvaez, C, Paez, J, Sotomayor, A, Garcia, H, Sanchez, G, David, T, Rico, A, Mony, P, Vaz, M, Bharathi, A V, Swaminathan, S, Kurpad, K Shankar AV, Jayachitra, KG, Kumar, N, Hospital, HAL, Mohan, V, Deepa, M, Parthiban, K, Anitha, M, Hemavathy, S, Rahulashankiruthiyayan, T, Anitha, D, Sridevi, K, Gupta, R, Panwar, RB, Mohan, I, Rastogi, P, Rastogi, S, Bhargava, R, Kumar, R, Thakur, J S, Patro, B, Lakshmi, PVM, Mahajan, R, Chaudary, P, Kutty, V Raman, Vijayakumar, K, Ajayan, K, Rajasree, G, Renjini, AR, Deepu, A, Sandhya, B, Asha, S, Soumya, HS, Kelishadi, R, Bahonar, A, Mohammadifard, N, Heidari, H, Yusoff, K, Ismail, TST, Ng, KK, Devi, A, Nasir, NM, Yasin, MM, Miskan, M, Rahman, EA, Arsad, MKM, Ariffin, F, Razak, SA, Majid, FA, Bakar, NA, Yacob, MY, Zainon, N, Salleh, R, Ramli, MKA, Halim, NA, Norlizan, SR, Ghazali, NM, Arshad, MN, Razali, R, Ali, S, Othman, HR, Hafar, CWJCW, Pit, A, Danuri, N, Basir, F, Zahari, SNA, Abdullah, H, Arippin, MA, Zakaria, NA, Noorhassim, I, Hasni, MJ, Azmi, MT, Zaleha, MI, Hazdi, KY, Rizam, AR, Sazman, W, Azman, A, Khatib, R, Khammash, U, Khatib, A, Giacaman, R, Iqbal, R, Afridi, A, Khawaja, R, Raza, A, Kazmi, K, Zatonski, W, Szuba, A, Zatonska, K, Ilow, R, Ferus, M, Regulska-Ilow, B, Rózanska, D, Wolyniec, M, Alkamel, Ali, M, Kruger, M A, Voster, H H, Schutte, A E, Wentzel-Viljoen, E, Eloff, FC, de Ridder, H, Moss, H, Potgieter, J, Roux, AA, Watson, M, de Wet, G, Olckers, A, Jerling, JC, Pieters, M, Hoekstra, T, Puoane, T, Igumbor, E, Tsolekile, L, Sanders, D, Naidoo, P, Steyn, N, Peer, N, Mayosi, B, Rayner, B, Lambert, V, Levitt, N, Kolbe-Alexander, T, Ntyintyane, L, Hughes, G, Swart, R, Fourie, J, Muzigaba, M, Xapa, S, Gobile, N, Ndayi, K, Jwili, B, Ndibaza, K, Egbujie, B, Rosengren, A, Boström, K Bengtsson, Gustavsson, A, Andreasson, M, Snällman, M, Wirdemann, L, Oguz, A, Imeryuz, N, Altuntas, Y, Gulec, S, Temizhan, A, Karsidag, K, Calik, KBT, Akalin, AAK, Caklili, OT, Keskinler, MV, Erbakan, AN, Yusufali, AM, Almahmeed, W, Swidan, H, Darwish, EA, Hashemi, ARA, Al-Khaja, N, Muscat-Baron, JM, Ahmed, SH, Mamdouh, TM, Darwish, WM, Abdelmotagali, MHS, Awed, SA Omer, Movahedi, GA, Hussain, F, Al Shaibani, H, Gharabou, RIM, Youssef, DF, Nawati, AZS, Salah, ZAR Abu, Abdalla, RFE, Al Shuwaihi, SM, Al Omairi, MA, Cadigal, OD, Alejandrino, R.S., Chifamba, J, Gwaunza, L, Terera, G, Mahachi, C, Murambiwa, P, Machiweni, T, Mapanga, R, Miller, Victoria, Mente, Andrew, Dehghan, Mahshid, Rangarajan, Sumathy, Zhang, Xiaohe, Swaminathan, Sumathi, Dagenais, Gilles, Gupta, Rajeev, Mohan, Viswanathan, Lear, Scott, Bangdiwala, Shrikant I, Schutte, Aletta E, Wentzel-Viljoen, Edelweiss, Avezum, Alvaro, Altuntas, Yuksel, Yusoff, Khalid, Ismail, Noorhassim, Peer, Nasheeta, Chifamba, Jephat, Diaz, Rafael, Rahman, Omar, Mohammadifard, Noushin, Lana, Fernando, Zatonska, Katarzyna, Wielgosz, Andreas, Yusufali, Afzalhussein, Iqbal, Romaina, Lopez-Jaramillo, Patricio, Khatib, Rasha, Rosengren, Annika, Li, Wei, Liu, Jiankang, Liu, Xiaoyun, Yin, Lu, Teo, Koon, Anand, Sonia, and Yusuf, Salim

Published
2017
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14. Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study

Author

Diaz, R, Orlandini, A, Linetsky, B, Toscanelli, S, Casaccia, G, Cuneo, JM Maini, Rahman, O, Yusuf, R, Azad, AK, Rabbani, KA, Cherry, HM, Mannan, A, Hassan, I, Talukdar, AT, Tooheen, RB, Khan, MU, Sintaha, M, Choudhury, T, Haque, R, Parvin, S, Avezum, A, Oliveira, GB, Marcilio, CS, Mattos, AC, Teo, K, Yusuf, S, Dejesus, J, Agapay, D, Tongana, T, Solano, R, Kay, I, Trottier, S, Rimac, J, Elsheikh, W, Heldman, L, Ramezani, E, Dagenais, G, Poirier, P, Turbide, G, Auger, D, De Bluts, A LeBlanc, Proulx, MC, Cayer, M, Bonneville, N, Lear, S, Gasevic, D, Corber, E, de Jong, V, Vukmirovich, I, Wielgosz, A, Fodor, G, Pipe, A, Shane, A, Lanas, F, Seron, P, Martinez, S, Valdebenito, A, Oliveros, M, Wei, Li, Lisheng, Liu, Chunming, Chen, Xingyu, Wang, Wenhua, Zhao, Hongye, Zhang, Xuan, Jia, Bo, Hu, Yi, Sun, Jian, Bo, Xiuwen, Zhao, Xiaohong, Chang, Tao, Chen, Hui, Chen, Qing, Deng, Xiaoru, Cheng, Xinye, He, Jian, Li, Juan, Li, Xu, Liu, Bing, Ren, Wei, Wang, Yang, Wang, Jun, Yang, Yi, Zhai, Manlu, Zhu, Fanghong, Lu, Jianfang, Wu, Yindong, Li, Yan, Hou, Liangqing, Zhang, Baoxia, Guo, Xiaoyang, Liao, Shiying, Zhang, Rongwen, Bian, Xiuzhen, Tian, Dong, Li, Di, Chen, Jianguo, Wu, Yize, Xiao, Tianlu, Liu, Peng, Zhang, Changlin, Dong, Ning, Li, Xiaolan, Ma, Yuqing, Yang, Rensheng, Lei, Minfan, Fu, Jing, He, Yu, Liu, Xiaojie, Xing, Qiang, Zhou, Lopez-Jaramillo, P, Lopez, PA Camacho, Garcia, R, Jurado, LJA, Gómez-Arbeláez, D, Arguello, JF, Dueñas, R, Silva, S, Pradilla, LP, Ramirez, F, Molina, DI, Cure-Cure, C, Perez, M, Hernandez, E, Arcos, E, Fernandez, S, Narvaez, C, Paez, J, Sotomayor, A, Garcia, H, Sanchez, G, David, T, Rico, A, Mony, P, Vaz, M, Bharathi, A V, Swaminathan, S, Kurpad, K Shankar AV, Jayachitra, KG, Kumar, N, Hospital, HAL, Mohan, V, Deepa, M, Parthiban, K, Anitha, M, Hemavathy, S, Rahulashankiruthiyayan, T, Anitha, D, Sridevi, K, Gupta, R, Panwar, RB, Mohan, I, Rastogi, P, Rastogi, S, Bhargava, R, Kumar, R, Thakur, J S, Patro, B, Lakshmi, PVM, Mahajan, R, Chaudary, P, Kutty, V Raman, Vijayakumar, K, Ajayan, K, Rajasree, G, Renjini, AR, Deepu, A, Sandhya, B, Asha, S, Soumya, HS, Kelishadi, R, Bahonar, A, Mohammadifard, N, Heidari, H, Yusoff, K, Ismail, TST, Ng, KK, Devi, A, Nasir, NM, Yasin, MM, Miskan, M, Rahman, EA, Arsad, MKM, Ariffin, F, Razak, SA, Majid, FA, Bakar, NA, Yacob, MY, Zainon, N, Salleh, R, Ramli, MKA, Halim, NA, Norlizan, SR, Ghazali, NM, Arshad, MN, Razali, R, Ali, S, Othman, HR, Hafar, CWJCW, Pit, A, Danuri, N, Basir, F, Zahari, SNA, Abdullah, H, Arippin, MA, Zakaria, NA, Noorhassim, I, Hasni, MJ, Azmi, MT, Zaleha, MI, Hazdi, KY, Rizam, AR, Sazman, W, Azman, A, Khatib, R, Khammash, U, Khatib, A, Giacaman, R, Iqbal, R, Afridi, A, Khawaja, R, Raza, A, Kazmi, K, Zatonski, W, Szuba, A, Zatonska, K, Ilow, R, Ferus, M, Regulska-Ilow, B, Rózanska, D, Wolyniec, M, Alkamel, Ali, M, Kruger, M A, Voster, H H, Schutte, A E, Wentzel-Viljoen, E, Eloff, FC, de Ridder, H, Moss, H, Potgieter, J, Roux, AA, Watson, M, de Wet, G, Olckers, A, Jerling, JC, Pieters, M, Hoekstra, T, Puoane, T, Igumbor, E, Tsolekile, L, Sanders, D, Naidoo, P, Steyn, N, Peer, N, Mayosi, B, Rayner, B, Lambert, V, Levitt, N, Kolbe-Alexander, T, Ntyintyane, L, Hughes, G, Swart, R, Fourie, J, Muzigaba, M, Xapa, S, Gobile, N, Ndayi, K, Jwili, B, Ndibaza, K, Egbujie, B, Rosengren, A, Boström, K Bengtsson, Gustavsson, A, Andreasson, M, Snällman, M, Wirdemann, L, Oguz, A, Imeryuz, N, Altuntas, Y, Gulec, S, Temizhan, A, Karsidag, K, Calik, KBT, Akalin, AAK, Caklili, OT, Keskinler, MV, Erbakan, AN, Yusufali, AM, Almahmeed, W, Swidan, H, Darwish, EA, Hashemi, ARA, Al-Khaja, N, Muscat-Baron, JM, Ahmed, SH, Mamdouh, TM, Darwish, WM, Abdelmotagali, MHS, Awed, SA Omer, Movahedi, GA, Hussain, F, Al Shaibani, H, Gharabou, RIM, Youssef, DF, Nawati, AZS, Salah, ZAR Abu, Abdalla, RFE, Al Shuwaihi, SM, Al Omairi, MA, Cadigal, OD, Alejandrino, R.S., Chifamba, J, Gwaunza, L, Terera, G, Mahachi, C, Murambiwa, P, Machiweni, T, Mapanga, R, Dehghan, Mahshid, Mente, Andrew, Zhang, Xiaohe, Swaminathan, Sumathi, Li, Wei, Mohan, Viswanathan, Iqbal, Romaina, Kumar, Rajesh, Wentzel-Viljoen, Edelweiss, Rosengren, Annika, Amma, Leela Itty, Avezum, Alvaro, Chifamba, Jephat, Diaz, Rafael, Khatib, Rasha, Lear, Scott, Lopez-Jaramillo, Patricio, Liu, Xiaoyun, Gupta, Rajeev, Mohammadifard, Noushin, Gao, Nan, Oguz, Aytekin, Ramli, Anis Safura, Seron, Pamela, Sun, Yi, Szuba, Andrzej, Tsolekile, Lungiswa, Wielgosz, Andreas, Yusuf, Rita, Hussein Yusufali, Afzal, Teo, Koon K, Rangarajan, Sumathy, Dagenais, Gilles, Bangdiwala, Shrikant I, Islam, Shofiqul, Anand, Sonia S, and Yusuf, Salim

Published
2017
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20. Association of dietary nutrients with blood lipids and blood pressure in 18 countries: a cross-sectional analysis from the PURE study

Author

Yusuf, S, Rangarajan, S, Teo, K K, Chow, C K, O'Donnell, M, Mente, A, Leong, D, Smyth, A, Joseph, P, Merchant, A, Islam, S, Zhang, M, Hu, W, Ramasundarahettige, C, Wong, G, Bangdiwala, S, Dyal, L, Casanova, A, Dehghan, M, Lewis, G, Aliberti, A, Arshad, A, Reyes, A, Zaki, A, Lewis, B, Zhang, B, Agapay, D, Hari, D, Milazzo, E, Ramezani, E, Hussain, F, Shifaly, F, McAlpine, G, Kay, I, Lindeman, J, Rimac, J, Swallow, J, Heldman, L, Mushtaha, M(a), Mushtaha, M(o), Trottier, M, Riggi, M, Aoucheva, N, Kandy, N, Mackie, P, Solano, R, Chin, S, Ramacham, S, Shahrook, S, Trottier, S, Tongana, T, ElSheikh, W, Iyengar, Y, McQueen, M, Hall, K, Keys, J, Wang, X, Keneth, J, Devanath, A, Diaz, R, Orlandini, A, Linetsky, B, Toscanelli, S, Casaccia, G, Cuneo, JM Maini, Rahman, O, Yusuf, R, Azad, AK, Rabbani, KA, Cherry, HM, Mannan, A, Hassan, I, Talukdar, AT, Tooheen, RB, Khan, MU, Sintaha, M, Choudhury, T, Haque, R, Parvin, S, Avezum, A, Oliveira, GB, Marcilio, CS, Mattos, AC, Teo, K, Dejesus, J, Elsheikh, W, Dagenais, G, Poirier, P, Turbide, G, Auger, D, De Bluts, A LeBlanc, Proulx, MC, Cayer, M, Bonneville, N, Lear, S, Gasevic, D, Corber, E, de Jong, V, Vukmirovich, I, Wielgosz, A, Fodor, G, Pipe, A, Shane, A, Lanas, F, Seron, P, Martinez, S, Valdebenito, A, Oliveros, M, Wei, Li, Lisheng, Liu, Chunming, Chen, Xingyu, Wang, Wenhua, Zhao, Hongye, Zhang, Xuan, Jia, Bo, Hu, Yi, Sun, Jian, Bo, Xiuwen, Zhao, Xiaohong, Chang, Tao, Chen, Hui, Chen, Qing, Deng, Xiaoru, Cheng, Xinye, He, Jian, Li, Juan, Li, Xu, Liu, Bing, Ren, Wei, Wang, Yang, Wang, Jun, Yang, Yi, Zhai, Manlu, Zhu, Fanghong, Lu, Jianfang, Wu, Yindong, Li, Yan, Hou, Liangqing, Zhang, Baoxia, Guo, Xiaoyang, Liao, Shiying, Zhang, Rongwen, Bian, Xiuzhen, Tian, Dong, Li, Di, Chen, Jianguo, Wu, Yize, Xiao, Tianlu, Liu, Peng, Zhang, Changlin, Dong, Ning, Li, Xiaolan, Ma, Yuqing, Yang, Rensheng, Lei, Minfan, Fu, Jing, He, Yu, Liu, Xiaojie, Xing, Qiang, Zhou, Lopez-Jaramillo, P, Lopez, PA Camacho, Garcia, R, Jurado, LJA, Gómez-Arbeláez, D, Arguello, JF, Dueñas, R, Silva, S, Pradilla, LP, Ramirez, F, Molina, DI, Cure-Cure, C, Perez, M, Hernandez, E, Arcos, E, Fernandez, S, Narvaez, C, Paez, J, Sotomayor, A, Garcia, H, Sanchez, G, David, T, Rico, A, Mony, P, Vaz, M, Bharathi, A V, Swaminathan, S, Kurpad, K Shankar AV, Jayachitra, KG, Kumar, N, Hospital, HAL, Mohan, V, Deepa, M, Parthiban, K, Anitha, M, Hemavathy, S, Rahulashankiruthiyayan, T, Anitha, D, Sridevi, K, Gupta, R, Panwar, RB, Mohan, I, Rastogi, P, Rastogi, S, Bhargava, R, Kumar, R, Thakur, J S, Patro, B, Lakshmi, PVM, Mahajan, R, Chaudary, P, Kutty, V Raman, Vijayakumar, K, Ajayan, K, Rajasree, G, Renjini, AR, Deepu, A, Sandhya, B, Asha, S, Soumya, HS, Kelishadi, R, Bahonar, A, Mohammadifard, N, Heidari, H, Yusoff, K, Ismail, TST, Ng, KK, Devi, A, Nasir, NM, Yasin, MM, Miskan, M, Rahman, EA, Arsad, MKM, Ariffin, F, Razak, SA, Majid, FA, Bakar, NA, Yacob, MY, Zainon, N, Salleh, R, Ramli, MKA, Halim, NA, Norlizan, SR, Ghazali, NM, Arshad, MN, Razali, R, Ali, S, Othman, HR, Hafar, CWJCW, Pit, A, Danuri, N, Basir, F, Zahari, SNA, Abdullah, H, Arippin, MA, Zakaria, NA, Noorhassim, I, Hasni, MJ, Azmi, MT, Zaleha, MI, Hazdi, KY, Rizam, AR, Sazman, W, Azman, A, Khatib, R, Khammash, U, Khatib, A, Giacaman, R, Iqbal, R, Afridi, A, Khawaja, R, Raza, A, Kazmi, K, Dans, A, Co, HU, Sanchez, JT, Pudol, L, Zamora-Pudol, C, Palileo-Villanueva, LAM, Aquino, MR, Abaquin, C, Pudol, SL, Cabral, ML, Zatonski, W, Szuba, A, Zatonska, K, Ilow, R, Ferus, M, Regulska-Ilow, B, Rózanska, D, Wolyniec, M, AlHabib, KF, Hersi, A, Kashour, T, Alfaleh, H, Alshamiri, M, Altaradi, HB, Alnobani, O, Bafart, A, Alkamel, N, Ali, M, Abdulrahman, M, Nouri, R, Kruger, A, Voster, H H, Schutte, A E, Wentzel-Viljoen, E, Eloff, FC, de Ridder, H, Moss, H, Potgieter, J, Roux, AA, Watson, M, de Wet, G, Olckers, A, Jerling, JC, Pieters, M, Hoekstra, T, Puoane, T, Igumbor, E, Tsolekile, L, Sanders, D, Naidoo, P, Steyn, N, Peer, N, Mayosi, B, Rayner, B, Lambert, V, Levitt, N, Kolbe-Alexander, T, Ntyintyane, L, Hughes, G, Swart, R, Fourie, J, Muzigaba, M, Xapa, S, Gobile, N, Ndayi, K, Jwili, B, Ndibaza, K, Egbujie, B, Rosengren, A, Bengtsson Boström, K, Gustavsson, A, Andreasson, M, Snällman, M, Wirdemann, L, Yeates, K, Sleeth, J, Kilonzo, K, Oguz, A, Imeryuz, N, Altuntas, Y, Gulec, S, Temizhan, A, Karsidag, K, Calik, KBT, Akalin, AAK, Caklili, OT, Keskinler, MV, Erbakan, AN, Yusufali, AM, Almahmeed, W, Swidan, H, Darwish, EA, Hashemi, ARA, Al-Khaja, N, Muscat-Baron, JM, Ahmed, SH, Mamdouh, TM, Darwish, WM, Abdelmotagali, MHS, Awed, SA Omer, Movahedi, GA, Al Shaibani, H, Gharabou, RIM, Youssef, DF, Nawati, AZS, Salah, ZAR Abu, Abdalla, RFE, Al Shuwaihi, SM, Al Omairi, MA, Cadigal, OD, Alejandrino, R.S., Chifamba, J, Gwaunza, L, Terera, G, Mahachi, C, Murambiwa, P, Machiweni, T, Mapanga, R, Mente, Andrew, Dehghan, Mahshid, Rangarajan, Sumathy, McQueen, Matthew, Dagenais, Gilles, Wielgosz, Andreas, Lear, Scott, Li, Wei, Chen, Hui, Wang, Yang, Diaz, Rafael, Avezum, Alvaro, Lopez-Jaramillo, Patricio, Seron, Pamela, Kumar, Rajesh, Gupta, Rajeev, Mohan, Viswanathan, Swaminathan, Sumathi, Kutty, Raman, Zatonska, Katarzyna, Iqbal, Romaina, Yusuf, Rita, Mohammadifard, Noushin, Khatib, Rasha, Nasir, Nafiza Mat, Ismail, Noorhassim, Oguz, Aytekin, Rosengren, Annika, Yusufali, Afzalhussein, Wentzel-Viljoen, Edelweiss, Puoane, Thandi, Chifamba, Jephat, Teo, Koon, Anand, Sonia S, and Yusuf, Salim

Published
2017
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21. Availability and affordability of blood pressure-lowering medicines and the effect on blood pressure control in high-income, middle-income, and low-income countries: an analysis of the PURE study data

Author

Yusuf, S, Rangarajan, S, Teo, K K, Chow, C K, O'Donnell, M, Mente, A, Leong, D, Smyth, A, Joseph, P, Islam, S, Zhang, M, Hu, W, Ramasundarahettige, C, Wong, G, Dayal, L, Casanova, A, Dehghan, M, Lewis, G, Aliberti, A, Reyes, A, Zaki, A, Lewis, B, Zhang, B, Agapay, D, Hari, D, Milazzo, E, Ramezani, E, Hussain, F, Shifaly, F, Kay, I, Rimac, J, Swallow, J, Heldman, L, Mushtaha, M(a), Mushtaha, M(o), Trottier, M, Aoucheva, N, Kandy, N, Mackie, P, Solano, R, Chin, S, Ramacham, S, Shahrook, S, Trottier, S, Tongana, T, ElSheikh, W, Lindeman, J, McQueen, M, Hall, K, Keys, J, Wang, X, Keneth, J, Devanath, A, Diaz, R, Orlandini, A, Linetsky, B, Toscanelli, S, Casaccia, G, Maini Cuneo, JM, Rahman, O, Yusuf, R, Azad, AK, Rabbani, KA, Cherry, HM, Mannan, A, Hassan, I, Talukdar, AT, Tooheen, RB, Khan, MU, Sintaha, M, Choudhury, T, Haque, R, Parvin, S, Avezum, A, Oliveira, GB, Marcilio, CS, Mattos, AC, Teo, K, Dejesus, J, Elsheikh, W, Dagenais, G, Poirier, P, Turbide, G, Auger, D, De Bluts, A LeBlanc, Proulx, MC, Cayer, M, Bonneville, N, Lear, S, Gasevic, D, Corber, E, de Jong, V, Vukmirovich, I, Wielgosz, A, Fodor, G, Pipe, A, Shane, A, Lanas, F, Seron, P, Martinez, S, Valdebenito, A, Oliveros, M, Wei, Li, Lisheng, Liu, Chunming, Chen, Xingyu, Wang, Wenhua, Zhao, Hongye, Zhang, JiaXuan, Bo, Hu, Yi, Sun, Jian, Bo, Xiuwen, Zhao, Xiaohong, Chang, Tao, Chen, Hui, Chen, Qing, Deng, Xiaoru, Cheng, Xinye, He, Jian, Li, Juan, Li, Xu, Liu, Bing, Ren, Wei, Wang, Yang, Wang, Jun, Yang, Yi, Zhai, Manlu, Zhu, Fanghong, Lu, Jianfang, Wu, Yindong, Li, Yan, Hou, Liangqing, Zhang, Baoxia, Guo, Xiaoyang, Liao, Shiying, Zhang, BianRongwen, TianXiuzhen, Dong, Li, Di, Chen, Jianguo, Wu, Yize, Xiao, Tianlu, Liu, Peng, Zhang, Changlin, Dong, Ning, Li, Xiaolan, Ma, Yuqing, Yang, Rensheng, Lei, Minfan, Fu, Jing, He, Yu, Liu, Xiaojie, Xing, Qiang, Zhou, Lopez-Jaramillo, P, Lopez, PA Camacho, Garcia, R, Jurado, LJA, Gómez-Arbeláez, D, Arguello, JF, Dueñas, R, Silva, S, Pradilla, LP, Ramirez, F, Molina, DI, Cure-Cure, C, Perez, M, Hernandez, E, Arcos, E, Fernandez, S, Narvaez, C, Paez, J, Sotomayor, A, Garcia, H, Sanchez, G, David, T, Rico, A, Mony, P, Vaz, M, Bharathi, A V, Swaminathan, S, Shankar, K, Kurpad, AV, Jayachitra, KG, Kumar, N, Hospital, HAL, Mohan, V, Deepa, M, Parthiban, K, Anitha, M, Hemavathy, S, Rahulashankiruthiyayan, T, Anitha, D, Sridevi, K, Gupta, R, Panwar, RB, Mohan, I, Rastogi, P, Rastogi, S, Bhargava, R, Kumar, R, Thakur, J S, Patro, B, Lakshmi, PVM, Mahajan, R, Chaudary, P, Kutty, V Raman, Vijayakumar, K, Ajayan, K, Rajasree, G, Renjini, AR, Deepu, A, Sandhya, B, Asha, S, Soumya, HS, Kelishadi, R, Bahonar, A, Mohammadifard, N, Heidari, H, Yusoff, K, Ismail, TST, Ng, KK, Devi, A, Nasir, NM, Yasin, MM, Miskan, M, Rahman, EA, Arsad, MKM, Ariffin, F, Razak, SA, Majid, FA, Bakar, NA, Yacob, MY, Zainon, N, Salleh, R, Ramli, MKA, Halim, NA, Norlizan, SR, Ghazali, NM, Arshad, MN, Razali, R, Ali, S, Othman, HR, Hafar, CWJCW, Pit, A, Danuri, N, Basir, F, Zahari, SNA, Abdullah, H, Arippin, MA, Zakaria, NA, Noorhassim, I, Hasni, MJ, Azmi, MT, Zaleha, MI, Hazdi, KY, Rizam, AR, Sazman, W, Azman, A, Khatib, R, Khammash, U, Khatib, A, Giacaman, R, Iqbal, R, Afridi, A, Khawaja, R, Raza, A, Kazmi, K, Dans, A, Co, HU, Sanchez, JT, Pudol, L, Zamora-Pudol, C, Palileo-Villanueva, LAM, Aquino, MR, Abaquin, C, Pudol, SL, Cabral, ML, Zatonski, W, Szuba, A, Zatonska, K, Ilow#, R, Ferus, M, Regulska-Ilow, B, Różańska, D, Wolyniec, M, AlHabib, KF, Hersi, A, Kashour, T, Alfaleh, H, Alshamiri, M, Altaradi, HB, Alnobani, O, Bafart, A, Alkamel, N, Ali, M, Abdulrahman, M, Nouri, R, Kruger, A, Voster, H H, Schutte, A E, Wentzel-Viljoen, E, Eloff, FC, de Ridder, H, Moss, H, Potgieter, J, Roux, AA, Watson, M, de Wet, G, Olckers, A, Jerling, JC, Pieters, M, Hoekstra, T, Puoane, T, Igumbor, E, Tsolekile, L, Sanders, D, Naidoo, P, Steyn, N, Peer, N, Mayosi, B, Rayner, B, Lambert, V, Levitt, N, Kolbe-Alexander, T, Ntyintyane, L, Hughes, G, Swart, R, Fourie, J, Muzigaba, M, Xapa, S, Gobile, N, Ndayi, K, Jwili, B, Ndibaza, K, Egbujie, B, Rosengren, A, Boström, K Bengtsson, Lindblad, U, Langkilde, P, Gustavsson, A, Andreasson, M, Snällman, M, Wirdemann, L, Pettersson, K, Moberg, E, Yeates, K, Sleeth, J, Kilonzo, K, Oguz, A, Akalin, AAK, Calik, KBT, Imeryuz, N, Temizhan, A, Alphan, E, Gunes, E, Sur, H, Karsidag, K, Gulec, S, Altuntas, Y, Yusufali, AM, Almahmeed, W, Swidan, H, Darwish, EA, Hashemi, ARA, Al-Khaja, N, Muscat-Baron, JM, Ahmed, SH, Mamdouh, TM, Darwish, WM, Abdelmotagali, MHS, Awed, SA Omer, Movahedi, GA, Shaibani, H Al, Gharabou, RIM, Youssef, DF, Nawati, AZS, Salah, ZAR Abu, Abdalla, RFE, Shuwaihi, SM Al, Omairi, MA Al, Cadigal, OD, Alejandrino, R.S., Chifamba, J, Gwaunza, L, Terera, G, Mahachi, C, Murambiwa, P, Machiweni, T, Mapanga, R, Attaei, Marjan W, Khatib, Rasha, McKee, Martin, Lear, Scott, Dagenais, Gilles, Igumbor, Ehimario U, AlHabib, Khalid F, Kaur, Manmeet, Kruger, Lanthe, Teo, Koon, Lanas, Fernando, Yusoff, Khalid, Oguz, Aytekin, Gupta, Rajeev, Yusufali, Afzalhussein M, Bahonar, Ahmad, Kutty, Raman, Rosengren, Annika, Mohan, Viswanathan, Avezum, Alvaro, Yusuf, Rita, Szuba, Andrzej, Rangarajan, Sumathy, Chow, Clara, and Yusuf, Salim

Published
2017
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27. Descriptive epidemiology of coronavirus disease 2019 in Nigeria, 27 February– 6 June 2020.

Author

Elimian, K. O., Ochu, C. L., Ilori, E., Oladejo, J., Igumbor, E., Steinhardt, L., Wagai, J., Arinze, C., Ukponu, W., Obiekea, C., Aderinola, O., Crawford, E., Olayinka, A., Dan-Nwafor, C., Okwor, T., Disu, Y., YinkaOgunleye, A., Kanu, N. E., Olawepo, O. A., and Aruna, O.

Abstract

The objective of this study was to describe the epidemiology of COVID-19 in Nigeria with a view of generating evidence to enhance planning and response strategies. A national surveillance dataset between 27 February and 6 June 2020 was retrospectively analysed, with confirmatory testing for COVID-19 done by real-time polymerase chain reaction (RT-PCR). The primary outcomes were cumulative incidence (CI) and case fatality (CF). A total of 40 926 persons (67% of total 60 839) had complete records of RT-PCR test across 35 states and the Federal Capital Territory, 12 289 (30.0%) of whom were confirmed COVID-19 cases. Of those confirmed cases, 3467 (28.2%) had complete records of clinical outcome (alive or dead), 342 (9.9%) of which died. The overall CI and CF were 5.6 per 100 000 population and 2.8%, respectively. The highest proportion of COVID-19 cases and deaths were recorded in persons aged 31–40 years (25.5%) and 61–70 years (26.6%), respectively; and males accounted for a higher proportion of confirmed cases (65.8%) and deaths (79.0%). Sixty-six per cent of confirmed COVID-19 cases were asymptomatic at diagnosis. In conclusion, this paper has provided an insight into the early epidemiology of COVID-19 in Nigeria, which could be useful for contextualising public health planning. [ABSTRACT FROM AUTHOR]

Published
2020
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28. Ab-initio study of the optical properties of beryllium-sulphur co-doped graphene.

Author

Olaniyan, O., Igumbor, E., Khaleed, A. A., Mirghni, A. A., and Manyala, N.

Subjects
*OPTICAL properties of graphene, *NANOELECTRONICS, *OPTOELECTRONICS
Abstract

Graphene is a carbon material with excellent properties, which makes it applicable in a myriad of applications. However, the range of the applications of graphene can be extended to the developing field of nanoelectronics and optoelectronics by doping it with heteroatoms. In this study, Be and S atoms were used to co-dope graphene. The impurity concentration was varied by increasing the size of the supercell from 2x2 through 4x4. First-principles calculations were performed to determine the dynamic stability, band structure, and optical characteristics of the system. The results of the phonon dispersion of beryllium and sulphur co-doped graphene (Be-S) show the absence of imaginary modes, suggesting that Be-S is dynamically stable. The analysis of the band structure indicates that it has a tunable indirect band-gap which increases with the impurity concentration. A band-gap magnitude is required in a graphene-based transistor. Thus, Be-S could be considered as a transistor material. As regards with the optical properties, it is observed that the optical transparency of the graphene in the ultraviolet region changes with the impurity concentration. The result shows that Be-S can be used to manipulate light waves for a device application. [ABSTRACT FROM AUTHOR]

Published
2019
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29. Induced defect levels of P and Al vacancy-complexes in [formula omitted]-SiC: A hybrid functional study.

Author

Igumbor, E., Olaniyan, O., Mapasha, R.E., Danga, H.T., Omotoso, E., and Meyer, W.E.

Subjects
*POINT defects, *ALUMINUM compounds, *METAL complexes, *FUNCTIONAL analysis, *ELECTRONIC structure
Abstract

Abstract The electronic behaviour of high-dose phosphorus implanted in 4 H -SiC is mainly desirable to obtained lower sheet resistance of 4 H -SiC. Al doping on the other hand acts as an acceptor, improves the dielectric properties of 4 H -SiC and has very low diffusivity in SiC. Using a hybrid density functional theory, we investigated the properties of Al and P defect-complexes in 4 H -SiC a wide band-gap semiconductor that is promising for applications in high-frequency and high-temperature electronic device. We show that vacancy-complexes formed by P Si and Al Si are more energetically stable than those formed by P C and Al C. The defects with silicon vacancy are predicted to experience more lattice distortion compared to those formed with carbon vacancy. While vacancy-complexes formed with P Si or P C and V C induced double donor levels, vacancy-complex formed with substitution of P and V Si induced negative-U charge state ordering. The Al with V C related vacancy-complexes induced deep single donor and acceptor levels, and Al with V Si induced only acceptor and negative-U ordering. [ABSTRACT FROM AUTHOR]

Published
2019
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30. Prediabetes and cardiovascular complications study (PACCS): international collaboration 4 years' summary and future direction.

Author

Nwose, E. U., Richards, R. S., Bwititi, P. T., Igumbor, E. O., Oshionwu, E. J., Okolie, K., Onyia, I. C., Pokhrel, A., Gyawali, P., Okuzor, J. N., Oguoma, V. M., Gardiner, F. W., and Wang, L.

Subjects
CARDIOVASCULAR diseases risk factors, PREDIABETIC state, MEDICAL screening, HYPERGLYCEMIA, HYPERTENSION, COMORBIDITY
Abstract

Objective: The prediabetes and cardiovascular complications studies proposes to develop a screening protocol for diabetes cardiovascular risk, and strategies for holistic management amongst others. Over 500 participants were recruited in the first 2 years of rural community research screening. Specific for this report, various published findings were reviewed. The objective is to summarize research outcomes and itemize limitations as they constitute basis of future directions. Results: Affordability and availability are major confounding behavioural change wheel factors in the rural community. 4.9% prevalence of prediabetes, which may be lower or non-significantly different in urban areas. Hyperglycaemia co-morbidity with dyslipidaemia (5.0%), obesity (3.1%) and hypertension (1.8%) were observed. Limitation of the study includes participants being mostly over 60 years old, which has created impetus for the Global Alliance on Chronic Diseases agenda on vulnerability of older adults to diabetes being a new direction of the collaboration. Other directions in Australia and Nepal focus on patients with chronic kidney disease with or without cardiovascular complications. This report highlights the need to translational research. [ABSTRACT FROM AUTHOR]

Published
2017
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32. A hybrid functional calculation of Tm3+ defects in germanium (Ge).

Author

Igumbor, E. and Meyer, W.E.

Subjects
*AB-initio calculations, *GERMANIUM, *DENSITY functional theory, *AXIAL loads, *LEWIS acidity
Abstract

In this work, we present ab-initio calculation results for the Tm 3+ interstitial ( Tm i 3 + ), vacancy–interstitial complex (V Ge -Tm i 3+ ) and substitutional ( Tm Ge 3 + ) defects in germanium (Ge) as determined by the density functional theory (DFT) using the Heyd, Scuseria, and Ernzerhof (HSE06) hybrid functional. We calculated the formation energies and the charge state transition levels of different configurations. Our results show that the Tm 3+ interstitial exists in the hexagonal configuration with low formation energy. The formation energies for V Ge − Tm i 3 + and Tm Ge 3 + were as low as 0.84 eV. The most energetically favourable defects were the V Ge − Tm i 3 + in the axial configuration and the Tm Ge 3 + . The Tm Ge 3 + and V Ge − Tm i 3 + introduced a single acceptor ϵ ( 0 / − 1 ) charge state transition level that was positioned deep in the middle of the band gap. The majority of the levels induced by the defects under investigation, were either shallow donor or acceptor level lying close to the band gap edges. [ABSTRACT FROM AUTHOR]

Published
2016
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34. Microbiological analysis of banknotes circulating in the Venda region of Limpopo province, South Africa.

Author

Igumbor, E. O., Obi, C. L., Bessong, P. O., Potgieter, N., and Mkasi, T. C.

Subjects
*MICROBIOLOGY, *BANK notes, *PAPER money, *PUBLIC health, *PATHOGENIC microorganisms, *OPPORTUNISTIC infections, *INFECTION, *COMMUNICABLE diseases
Abstract

The article identifies microbial contaminants of used and new banknotes in circulation in the Venda region of Limpopo Province, South Africa and highlights the implications for public health in this locality. Results show that bacteria and/or fungi were isolated from 96% of the used banknotes, and none from the new (control) notes. The study also reveals that the low-denomination notes were the most contaminated. The researchers notes that infected currency is identified as a potential public health hazard, as pathogens can be spread by circulating banknotes. Through handling of contaminated currency, immunocompromised persons stand the risk of acquiring opportunistic infections.

Published
2007

35. Building capacity without disrupting health services: public health education for Africa through distance learning

Author

Igumbor Ehi, Alexander Lucy, and Sanders David

Subjects
Medicine (General), R5-920, Public aspects of medicine, RA1-1270
Abstract

Abstract The human resources crisis in Africa is especially acute in the public health field. Through distance education, the School of Public Health of the University of the Western Cape, South Africa, has provided access to master's level public health education for health professionals from more than 20 African countries while they remain in post. Since 2000, interest has increased overwhelmingly to a point where four times more applications are received than can be accommodated. This home-grown programme remains sensitive to the needs of the target learners while engaging them in high-quality learning applied in their own work contexts. This brief paper describes the innovative aspects of the programme, offering some evaluative indications of its impact, and reviews how the delivery of text-led distance learning has facilitated the realization of the objectives of public health training. Strategies are proposed for scaling up such a programme to meet the growing need in this essential area of health human resource capacity development in Africa.

Published
2009
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36. Prevalence, haemolytic and haemagglutination activities and antibiotic susceptibility profiles of Campylobacter spp. isolated from human diarrhoeal stools in Vhembe District, South Africa.

Author

Samie, A., Ramalivhana, J., Igumbor, E. O., and Obi, C. L.

Subjects
*HEMOLYSIS & hemolysins, *BLOOD agglutination, *ANTIBIOTICS, *CAMPYLOBACTER, *FECES
Abstract

Campylobacter species are increasingly being recognized as agents of gastroenteritis worldwide. However, data on the pathogenic characteristics of the organism isolated in rural communities in South Africa are lacking. In this study, the prevalence of Campylobacter spp. from diarrhoeal stools, haemolytic and haemagglutinating activities of the isolates, and antibiotic susceptibility profiles, including minimum inhibitory concentration (MIC) patterns to different antibiotics, were determined using the standard microbiological techniques. Campylobacter spp. were isolated from individuals of all age-groups; however, the infection rate was higher among individuals aged less than two years (30.4%). Of 115 Campylobacter strains isolated, polymerase chain reaction (PCR) analysis indicated that 98 (85%) were C. jejuni, while 17 (15%) were C. coli. Seventy-one (62%) of the strains showed haemolysis on human blood, and 80% agglutinated human blood, whereas 22.6% were beta-lactamase-positive. Resistance to antimicrobials, such as erythromycin, ciprofloxacin, vancomycin, and fusidic acid, was high. Increased resistance to macrolide and quinolone antibiotics poses major risks for treatment failure. Haemolytic and haemagglutinating activities may be useful in preliminary characterization of pathogenic strains in settings where Campylobacter-associated infections are common. [ABSTRACT FROM AUTHOR]

Published
2007

37. Electrical characterisation of deep level defects created by bombarding the n-type 4H-SiC with 1.8 MeV protons.

Author

Omotoso, E., Paradzah, A.T., Janse Van Rensburg, P.J., Legodi, M.J., Auret, F.D., Igumbor, E., Danga, H.T., Diale, M., and Meyer, W.E.

Subjects
*SCHOTTKY-barrier diodes testing, *DEEP level transient spectroscopy, *SILICON carbide, *ARGON, *ELECTRON traps
Abstract

Abstract We have characterised the deep level defects present before and after annealing the proton-irradiated Ni/nitrogen-doped 4 H -SiC Schottky barrier diodes (SBDs) using deep level transient spectroscopy. The bombardment of the sample was carried out at a fluence of 1.0 × 1012 cm−2. The quality of the Ni/4H-SiC SBDs was evaluated before and after proton irradiation and annealing by current–voltage (I-V) and capacitance–voltage (C-V) measurements, carried out at room temperature (300 K). The I-V and C-V results revealed extensive degradation of the diodes properties after proton irradiation at the aforementioned fluence. Rectification properties of the Ni/4H-SiC SBDs recovered gradually after annealing in flowing argon at temperatures varying from 125 to 625 °C. The presence of four electron traps (E c – 0.10, E c – 0.13, E c – 0.18 and E c – 0.69 eV) was observed in as-grown Ni/4H-SiC SBDs. Deep level defects, E c – 0.42 and E c – 0.76 eV, were revealed after annealing the proton-irradiated SBDs up to 225 °C. The two defects observed at 225 °C later annealed out at 425 °C, causing a significant change in the spectrum. The annealing out of E c – 0.42 and E c – 0.76 eV at 425 °C was concurrent with detection of two electron traps, E c – 0.31 and E c – 0.62 eV. We speculate that the defects E c – 0.42 and E c – 0.76 eV have a link or relationship with defects E c – 0.31 and E c – 0.62 eV, respectively. The defect, E c – 0.31 eV, was stable up to high-temperature annealing and was attributed to a carbon interstitial. [ABSTRACT FROM AUTHOR]

Published
2018
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38. A systematic study of the stability, electronic and optical properties of beryllium and nitrogen co-doped graphene.

Author

Olaniyan, O., Maphasha, R.E., Madito, M.J., Khaleed, A.A., Igumbor, E., and Manyala, N.

Subjects
*ELECTRIC properties of graphene, *OPTICAL properties of graphene, *DOPING agents (Chemistry), *AB-initio calculations, *BERYLLIUM, *NITROGEN
Abstract

Ab-initio calculations within the framework of density functional theory (DFT) have been performed to study the stability, electronic and optical properties of Be and N singly doped and co-doped graphene. The effect of the dopants concentration and isomerization on the electronic and the optical properties of these systems have been studied. It has been found that Be-N is more stable than Be-doped graphene. The transition from semi-metallicity as in the case of pristine graphene to semi-conducting of graphene doped separately with Be, N and pairs of Be-N has been observed. Both Be and Be-N co-doped graphene exhibit p-type character. Moreover, the size of the band-gap observed in these aforementioned systems increases with the impurity concentrations. All the systems investigated are transparent within the frequency interval of 7.0–10 eV for parallel electromagnetic polarization. In general, we observed that the optical properties of the doped systems studied, respond to doping concentration differently across the electromagnetic spectrum with respect to the polarization field vectors. The results of our study demonstrate Be-N co-doped graphene to be a more realistic p-type semiconductor than Be-doped graphene and the band-gap can be tailored to meet the requirements of specific applications in nanoelectronic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Published
2018
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39. Prevalence of intestinal parasitic and bacterial pathogens in diarrhoeal and non-diarroeal human stools from Vhembe district, South Africa.

Author

Samie A, Guerrant RL, Barrett L, Bessong PO, Igumbor EO, Obi CL, Samie, A, Guerrant, R L, Barrett, L, Bessong, P O, Igumbor, E O, and Obi, C L

Abstract

In the present study, a cross-sectional survey of intestinal parasitic and bacterial infections in relation to diarrhoea in Vhembe district and the antimicrobial susceptibility profiles of isolated bacterial pathogens was conducted. Stool samples were collected from 528 patients attending major public hospitals and 295 children attending two public primary schools and were analyzed by standard microbiological and parasitological techniques. Entamoeba histolytica/E. dispar (34.2%) and Cryptosporidium spp. (25.5%) were the most common parasitic causes of diarrhoea among the hospital attendees while Giardia lamblia (12.8%) was the most common cause of diarrhoea among the primary school children (p < 0.05). Schistosoma mansoni (14.4%) was more common in non-diarrhoeal samples at both hospitals (16.9%) and schools (17.6%). Campylobacter spp. (24.9%), Aeromonas spp. (20.8%), and Shigella spp. (8.5%) were the most common bacterial causes of diarrhoea among the hospital attendees while Campylobacter (12.8%) and Aeromonas spp. (12.8%) were most common in diarrhoeal samples from school children. Vibrio spp. was less common (3% in the hospitals) and were all associated with diarrhoea. Antimicrobial resistance was common among the bacterial isolates but ceftriaxone (91%) and ciprofloxacin (88.6%) showed stronger activities against all the organisms. The present study has demonstrated that E. histolytica/dispar, Cryptosporidium, Giardia, and Cyclospora are common parasitic causes of diarrhoea in Vhembe district while Campylobacter spp. and Aeromonas are the most common bacterial causes of diarrhoea in Vhembe district of South Africa. [ABSTRACT FROM AUTHOR]

Published
2009

40. Prevalence, pathogenesis, antibiotic susceptibility profiles, and in-vitro activity of selected medicinal plants against Aeromonas isolates from stool samples of patients in the Venda region of South Africa.

Author

Obi, C. L., Ramalivhana, J., Samie, A., and Igumbor, E. O.

Subjects
*MEDICINAL plants, *AEROMONAS, *ANTIBIOTICS, *FECES, *PATIENTS
Abstract

The prevalence, pathogenic indices, such as haemolytic and haemagglutinating activities, antibiograms, and in-vitro activities of local medicinal plants against Aeromonas isolates in Vhembe district of Limpopo province, South Africa, were studied using standard microbiological methods. In total, 309 diarrhoeic stool samples were collected from patients attending five health centres in the region during December 2004-May 2005. Aeromonas species were identified using the API 20E system. The haemagglutinating and haemolytic activities of isolates on human, sheep, pig and chicken red blood cells were investigated. Antibiotic susceptibility profiles of the isolates to several antibiotics and in-vitro activity of local medicinal plants were also ascertained using previously-reported schemes. Results showed that 104 (33.6%) of the 309 samples were positive for Aeromonas species, of which 89 (85.6%) were Aeromonas hydrophila, 12 (11.5%) A. sobria, and three (2.9%) A. caviae. All strains of A. hydrophila and A. caviae produced haemolysis on sheep blood, while eight of the 12 A. sobria strains were haemolytic on sheep blood. The haemolytic activities of the isolates were variable on other red blood cells tested. High level of resistance was observed to amoxicillin and ampicillin, followed by cefuroxime (79%), chloramphenicol (74%), and erythromycin (65%). The carbapenems were the most active drugs with only 7% resistance to meropenem and 11% to imipenem. About 12% of the isolates were resistant to ciprofloxacin. The extracts of three of seven medicinal plants tested showed inhibitory activity against all Aeromonas isolates; these included acetone and hexane extracts of Pterocarpus angolensis, Syzygium cordatum, and Zornia milneana. The results suggest a high prevalence of Aeromonas species in the region. The isolates demonstrated multiple resistant profiles to different antibiotics tested. Some local medicinal plants were inhibitory to Aeromonas isolates, indicating a potential role in the management of Aeromonas-related infections. Structural elucidation of the active components may pave the way for the discovery of candidate templates for eventual drug design. Most isolates possessed important virulence characteristics based on their haemolytic and haemagglutinating ability. However, the genetic characterization of the isolates will further confirm their pathogenicity and the origin of multiple antibiotic resistance. [ABSTRACT FROM AUTHOR]

Published
2007

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