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414 results on '"Ma, Yinghua"'

1. Epsilon toxin-producing Clostridium perfringens colonize the MS gut and epsilon toxin overcomes immune privilege

Author

Ma, Yinghua, Sannino, David, Linden, Jennifer R, Haigh, Sylvia, Zhao, Baohua, Grigg, John B, Zumbo, Paul, Dündar, Friederike, Butler, Daniel J, Profaci, Caterina P, Telesford, Kiel M, Winokur, Paige N, Rumah, Kareem R, Gauthier, Susan A, Fischetti, Vincent A, McClane, Bruce A, Uzal, Francisco A, Zexter, Lily, Mazzucco, Michael, Rudick, Richard, Danko, David, Balmuth, Evan, Nealon, Nancy, Perumal, Jai, Kaunzner, Ulrike W, Brito, Ilana L, Chen, Zhengming, Xiang, Jenny Z, Betel, Doron, Daneman, Richard, Sonnenberg, Gregory F, Mason, Christopher E, and Vartanian, Timothy

Subjects
Multiple Sclerosis, Neurosciences, Brain Disorders, Neurodegenerative, Autoimmune Disease, 2.1 Biological and endogenous factors, Aetiology, Neurological, Animals, Humans, Clostridium perfringens, Gastrointestinal Microbiome, Immune Privilege, Lymphocytes, Encephalomyelitis, Autoimmune, Experimental, Autoimmunity, Demyelinating disorders, Microbiology, Multiple sclerosis, Toxins/drugs/xenobiotics, Medical and Health Sciences, Immunology
Abstract

Multiple sclerosis (MS) is a complex disease of the CNS thought to require an environmental trigger. Gut dysbiosis is common in MS, but specific causative species are unknown. To address this knowledge gap, we used sensitive and quantitative PCR detection to show that people with MS were more likely to harbor and show a greater abundance of epsilon toxin-producing (ETX-producing) strains of C. perfringens within their gut microbiomes compared with individuals who are healthy controls (HCs). Isolates derived from patients with MS produced functional ETX and had a genetic architecture typical of highly conjugative plasmids. In the active immunization model of experimental autoimmune encephalomyelitis (EAE), where pertussis toxin (PTX) is used to overcome CNS immune privilege, ETX can substitute for PTX. In contrast to PTX-induced EAE, where inflammatory demyelination is largely restricted to the spinal cord, ETX-induced EAE caused demyelination in the corpus callosum, thalamus, cerebellum, brainstem, and spinal cord, more akin to the neuroanatomical lesion distribution seen in MS. CNS endothelial cell transcriptional profiles revealed ETX-induced genes that are known to play a role in overcoming CNS immune privilege. Together, these findings suggest that ETX-producing C. perfringens strains are biologically plausible pathogens in MS that trigger inflammatory demyelination in the context of circulating myelin autoreactive lymphocytes.

Published
2023

3. Hard Exudates Segmentation in Diabetic Retinopathy Using DiaRetDB1

Author

Ma Yinghua, Yang Heng, R. Amarnath, and Zeng Hui

Subjects
Deep learning, U-Net, diabetic retinopathy, hard exudates, DiaRetDB1, Electrical engineering. Electronics. Nuclear engineering, TK1-9971
Abstract

Diabetic retinopathy (DR) poses a major challenge in vision care, often leading to partial or complete limited vision in adults. Early and accurate detection of DR is essential for timely intervention and effective patient management. One critical aspect of DR diagnosis is identifying hard exudates in retinal images. Using deep tech or computer-aided methods, ophthalmologists can gain detailed insights into retinal health, facilitating precise diagnosis and treatment planning. However, the availability of medical image data in open datasets is often limited, making deep analysis challenging. To address this issue, we introduce a U-Net deep learning model, specifically modified and designed to segment hard exudates effectively, even with a limited dataset. In our study, the model is trained and tested on 89 original images from the DiaRetDB1 dataset, supplemented with augmented image to improve robustness. Despite the small dataset, our modified U-Net achieves high sensitivity, specificity, precision, and accuracy, culminating in an impressive F1 score of 0.9754. These results demonstrate the potential of our approach to improve DR diagnosis with limited resources. By adapting existing deep learning models, our research shows significant enhancements in diagnostic accuracy for DR. However, further validation with larger datasets and comparisons with other methods are necessary to confirm our findings. This study contributes to better detection of hard exudates in DR, ultimately leading to improved patient outcomes.

Published
2024
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5. Time from injury to hip-fracture surgery in low-income and middle-income regions: a secondary analysis of data from the International Orthopaedic Multicentre Study in Fracture Care (INORMUS)

Author

Guyatt, Gordon, Petrisor, Brad, Thabane, Lehana, Boniface, Respicious, Browner, Bruce, Pollak, Andrew, Slobogean, Gerard, Schemitsch, Emil, McKay, Paula, Tai, Kerry, Heels-Ansdell, Diane, Buckingham, Lisa, Norton, Robyn, Zhang, Jing, Parveen, Samina, Bhaumik, Soumyadeep, Morshed, Saam, Mackechnie, Madeline C., Zhang, Zhentao, Ma, Yinghua, Qin, Yanguo, Hu, Sanbao, Qi, Baochang, Dai, Wenjie, Cai, Xinyu, Rui, Gang, Chen, Hua, Shetty, Vijay, Dumbre Patil, Sampat, Patil, Sanjay, Shrivastava, Sandeep, Mittal, Ravi, Jepegnanam, Thilak Samuel, Mahajan, Anupam, Chhabra, Harvinder Singh, N, Rajagopalan, Amaravathi, Rajkumar S., Dhillon, Mandeep S., Chase, Asolie, Bhavsar, Neel M., Saadat, Soheil, Byanjankar, Subin, Qadir, Raja Irfan, Tabu, Irewin Alagar, Ponggsamakthai, Wanjak, Sa-ngasoongsong, Paphon, Subramanian, Panchu, Ndeleva, Benjamin Muluku, Lutomia, Mark, Otseyeno, Fred Mathew Toboso, Mwangi, Geoffrey Chege, Ndasi, Henry Tanyi, Konadu-Yeboah, Dominic, Firth, Gregory, Marealle, Paul, Temu, Rogers, Mutanda, Tony, Rio, Marcelo, Quintero, Jose Eduardo, Zuluaga, Mauricio, Minueza, Tomás, Madrigal, Ricardo, Ylizaliturri, Manuel, Garuz, Mario, Segovia Altieri, Julio, Escalante Elguezabal, Igor A., Armstrong, Elizabeth, Rogers, Kris, Li, Chuan Silvia, Jagnoor, Jagnoor, Moroz, Paul, Oguzie, Gerald Chukwuemeka, Hailu, Samuel, Miclau, Theodore, III, de la Huerta, Fernando, Martinez-Ruiz, Jose de Jesus, Bidolegui, Fernando, Zhou, Junlin, Ma, Xinlong, Wu, Bo, Sancheti, Parag, Quang, La Ngoc, Baigi, Vali, Haddadi, Mashyaneh, Tian, Maoyi, Sprague, Sheila, Devereaux, P J, Bhandari, Mohit, and Ivers, Rebecca

Published
2024
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8. Differentiated impacts of short-term exposure to fine particulate constituents on infectious diseases in 507 cities of Chinese children and adolescents: A nationwide time-stratified case-crossover study from 2008 to 2021

Author

Chen, Li, Yuan, Wen, Geng, Mengjie, Xu, Rongbin, Xing, Yi, Wen, Bo, Wu, Yao, Ren, Xiang, Shi, Yue, Zhang, Yi, Song, Xinli, Qin, Yang, Wang, RuoLin, Jiang, Jianuo, Dong, Ziqi, Liu, Jieyu, Guo, Tongjun, Song, Zhiying, Wang, Liping, Ma, Yinghua, Dong, Yanhui, Song, Yi, and Ma, Jun

Published
2024
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9. Matching actions to needs: shifting policy responses to the changing health needs of Chinese children and adolescents

Author

Chen, Tian-Jiao, Dong, Bin, Dong, Yanhui, Li, Jing, Ma, Yinghua, Liu, Dongshan, Zhang, Yuhui, Xing, Yi, Zheng, Yi, Luo, Xiaomin, Tao, Fangbiao, Ding, Yanqing, Hu, Peijin, Zou, Zhiyong, Pan, Bailin, Tang, Ping, Luo, Dongmei, Liu, Yunfei, Li, Luo, Li, Geffrey Nan, Tian, Xiaobo, Huang, Xiaona, Song, Yi, Ma, Jun, and Sawyer, Susan M

Published
2024
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13. Improvement and exacerbation of multiple disparities in sexually transmitted infections among children and adolescents aged 6–22 years: An analysis of national surveillance data from 2013 to 2021.

Author

Zhang, Yi, Geng, Mengjie, Xing, Yi, Ren, Xiang, Chen, Li, Liu, Jieyu, Song, Xinli, Qin, Yang, Wang, RuoLin, Jiang, Jianuo, Guo, Tongjun, Yuan, Wen, Ma, Yinghua, Ma, Jun, Wang, Liping, Song, Yi, and Dong, Yanhui

Subjects
SEXUALLY transmitted diseases, SYPHILIS, SEX education, HIV, TEENAGERS, COMMUNICABLE diseases, CHILD sexual abuse
Abstract

To investigate the progress of disparities in human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), gonorrhea, and syphilis among children and adolescents aged 6–22 years in China during 2013–2021. A total of 614 325 cases data were extracted from the Chinese Information System for Infectious Diseases Control and Prevention during 2013–2021. Puberty health education data were drew from the Student Health Surveillance in 2021. Disparity patterns and average annual percentage changes (AAPCs) in sexually transmitted infections (STIs) incidence or new cases in China were examined using descriptive statistics and joinpoint regression. The incidence across 345 cities was stratified by gross domestic product (GDP). Between 2013 and 2021, there were 614 325 reported cases of HIV/AIDS, gonorrhea, and syphilis among children and adolescents aged 6–22, with an annual average incidence of 24.0967 per 100 000. The expansion of HIV/AIDS has halted, yet the surge in gonorrhea and syphilis remains notably pronounced. The ratio of male to female AIDS incidence increased from 2.75 (2.60, 2.90) to 7.13 (6.68, 7.62), but that of syphilis changed from 0.33 (0.32, 0.34) to 0.56 (0.55, 0.57). Students and out‐of‐school individuals aged 13–15 experienced a notably high increase in STI cases, surpassing other age groups, with an average annual percentage increase of 29.2% and 26.3%, respectively. Nonstudents consistently had a higher incidence rate than students, with an IRR reaching 31.80 (31.24, 32.37) in 2021. A noticeable clustering pattern of new cases emerged in the southeastern region of the Heihe‐Tengchong line, extending inland from the coastal areas. Districts and counties with lower rates of puberty sexual health education tended to have higher average STI incidence rates. At the prefecture and city levels, there was a noticeable upward trend on average STI incidence rates in cities with per capita GDPs. Strategies to address those disparities include promoting equitable health education, and widespread sexual health education, particularly in areas with limited access to education and experiencing rapid economic development. The effectiveness of sexual health education intervention needs to be further evaluated in well‐designed studies. [ABSTRACT FROM AUTHOR]

Published
2024
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14. Epsilon toxin-producing Clostridium perfringens colonize the multiple sclerosis gut microbiome overcoming CNS immune privilege

Author

Ma, Yinghua, Sannino, David, Linden, Jennifer R., Haigh, Sylvia, Zhao, Baohua, Grigg, John B., Zumbo, Paul, Dundar, Friederike, Butler, Daniel, Profaci, Caterina P., Telesford, Kiel, Winokur, Paige N., Rumah, Kareem R., Gauthier, Susan A., Fischetti, Vincent A., McClane, Bruce A., Uzal, Francisco A., Zexter, Lily, Mazzucco, Michael, Rudick, Richard, Danko, David, Balmuth, Evan, Nealon, Nancy, Perumal, Jai, Kaunzner, Ulrike, Brito, Ilana L., Chen, Zhengming, Xiang, Jenny Z., Betel, Doron, Daneman, Richard, Sonnenberg, Gregory F., Mason, Christopher E., and Vartanian, Timothy

Subjects
Multiple sclerosis -- Genetic aspects -- Development and progression -- Care and treatment, Clostridium -- Genetic aspects -- Health aspects, Bacterial toxins -- Health aspects, Central nervous system -- Genetic aspects -- Health aspects, Health care industry
Abstract

Multiple sclerosis (MS) is a complex disease of the CNS thought to require an environmental trigger. Gut dysbiosis is common in MS, but specific causative species are unknown. To address this knowledge gap, we used sensitive and quantitative PCR detection to show that people with MS were more likely to harbor and show a greater abundance of epsilon toxin- producing (ETX-producing) strains of C. perfringens within their gut microbiomes compared with individuals who are healthy controls (HCs). Isolates derived from patients with MS produced functional ETX and had a genetic architecture typical of highly conjugative plasmids. In the active immunization model of experimental autoimmune encephalomyelitis (EAE), where pertussis toxin (PTX) is used to overcome CNS immune privilege, ETX can substitute for PTX. In contrast to PTX- induced EAE, where inflammatory demyelination is largely restricted to the spinal cord, ETX-induced EAE caused demyelination in the corpus callosum, thalamus, cerebellum, brainstem, and spinal cord, more akin to the neuroanatomical lesion distribution seen in MS. CNS endothelial cell transcriptional profiles revealed ETX-induced genes that are known to play a role in overcoming CNS immune privilege. Together, these findings suggest that ETX-producing C. perfringens strains are biologically plausible pathogens in MS that trigger inflammatory demyelination in the context of circulating myelin autoreactive lymphocytes., Introduction Multiple sclerosis (MS) lesions are centered on postcapillary venules (1, 2), and impairment of blood-brain barrier (BBB) function is considered the earliest event in lesion evolution, paving the way [...]

Published
2023
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15. Secular Trends in Blood Pressure and Overweight and Obesity in Chinese Boys and Girls Aged 7 to 17 Years From 1995 to 2014

Author

Dong, Yanhui, Ma, Jun, Song, Yi, Ma, Yinghua, Dong, Bin, Zou, Zhiyong, and Prochaska, Judith J

Subjects
Biomedical and Clinical Sciences, Cardiovascular Medicine and Haematology, Clinical Sciences, Obesity, Pediatric, Nutrition, Prevention, Aetiology, 2.4 Surveillance and distribution, Cardiovascular, Metabolic and endocrine, Stroke, Adolescent, Blood Pressure, Blood Pressure Determination, Body Mass Index, Child, Comorbidity, Cross-Sectional Studies, Female, Follow-Up Studies, Humans, Hypertension, Male, Overweight, Population Surveillance, Prevalence, Retrospective Studies, Taiwan, Time Factors, blood pressure, child, hypertension, obesity, overweight, Cardiorespiratory Medicine and Haematology, Public Health and Health Services, Cardiovascular System & Hematology, Cardiovascular medicine and haematology, Clinical sciences
Abstract

The current study aimed to assess the secular trends in overweight and obesity status and high blood pressure (HBP) in Chinese children and adolescents for 2 decades. Data on 943 128 participants aged 7 to 17 years were obtained from the Chinese National Survey on Students' Constitution and Health from 1995 to 2014. The population attributable risk of overweight status for HBP was calculated. The prevalence of overweight increased from 4.3% in 1995 to 18.4% in 2014, whereas HBP prevalence fluctuated in the range of 4.4% to 6.4% during the same time period, the lowest in 2005. Within each survey year, blood pressure levels and HBP prevalence increased with higher body mass index. Notably, the population attributable risk of HBP because of being overweight steadily increased from 6.3% in 1995 to 19.2% in 2014. The same trends of linear growth for obesity, fluctuating blood pressure, and its sustained increasing population attributable risk for overweight also occurred among the domestic 29 provinces. Despite dramatic increases in overweight prevalence among Chinese children from 1995 to 2014, the HBP prevalence remained relatively stable, suggesting that other independent factors are affecting HBP trends to a greater extent. Yet, over time, the magnitude of the impact of being overweight or obese on HBP increased sharply, predicting looming heavy burden of HBP. Reductions in overweight status may aid in preventing HBP so as to prevent coronary risk in adulthood.

Published
2018

17. Hierarchical Sentiment Estimation Model for Potential Topics of Individual Tweets

Author

Ji, Qian, Dai, Yilin, Ma, Yinghua, Liu, Gongshen, Zhang, Quanhai, Lin, Xiang, Filipe, Joaquim, Editorial Board Member, Ghosh, Ashish, Editorial Board Member, Prates, Raquel Oliveira, Editorial Board Member, Zhou, Lizhu, Editorial Board Member, Yang, Haiqin, editor, Pasupa, Kitsuchart, editor, Leung, Andrew Chi-Sing, editor, Kwok, James T., editor, Chan, Jonathan H., editor, and King, Irwin, editor

Published
2020
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18. Collaborative Attention Network for Natural Language Inference

Author

Zhang, Shiyi, Ma, Yinghua, Li, Shenghong, Sun, Weikai, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zhang, Junjie James, Series Editor, Wang, Wei, editor, Liu, Xin, editor, Na, Zhenyu, editor, Jia, Min, editor, and Zhang, Baoju, editor

Published
2020
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19. Similar Cluster Based Continuous Bag-of-Words for Word Vector Training

Author

Sun, Weikai, Ma, Yinghua, Li, Shenghong, Zhang, Shiyi, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zhang, Junjie James, Series Editor, Wang, Wei, editor, Liu, Xin, editor, Na, Zhenyu, editor, Jia, Min, editor, and Zhang, Baoju, editor

Published
2020
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27. Delays in hospital admissions in patients with fractures across 18 low-income and middle-income countries (INORMUS): a prospective observational study

Author

Bhandari, Mohit, Devereaux, PJ, Guyatt, Gordon, Petrisor, Brad, Thabane, Lehana, Boniface, Respicious L., Browner, Bruce, de la Huerta, Fernando, Ivers, Rebecca Q, Miclau, Theodore, III, Moroz, Paul, Pollak, Andrew, Slobogean, Gerard, Sancheti, Parag, Schemitsch, Emil, Zhou, Junlin, Sprague, Sheila, McKay, Paula, Li, Chuan Silvia, Mundi, Raman, O'Hara, Nathan, Heels-Ansdell, Diane, Buckingham, Lisa, Simunovic, Nicole, Jagnoor, Jagnoor, Norton, Robyn, Zhang, Jing, Tian, Maoyi, Bhaumik, Soumyadeep, Parveen, Samina, Morshed, Saam, MacKechnie, Madeline C., Liu, Yang, Zhao, Yanrui, Li, Junfei, Zhang, Haoran, Zhang, Zhentao, Zhang, Wei, Guo, Tao, Chen, Guang, Jia, Zichao, Yang, Jianzhong, Kang, Lixing, Zhang, Peng, Ma, Haoqing, Liu, Donghai, Ma, Yinghua, Qin, Yanguo, Wang, Jincheng, Liu, He, Ma, Xinlong, Ma, Jianxiong, Jia, Haobo, Cui, Shuangshuang, Zhao, Zhihu, Fu, Lin, Jiang, Hongqiang, Lv, Jianwei, Hu, Sanbao, Wang, Yongwei, Sun, Mingyao, Tao, Shuqing, Qi, Baochang, Gao, Ming, Wu, Bo, Zhi, Chunsheng, Xing, Ben, Yang, Jun, Dai, Wenjie, Lu, Duo, He, Shisheng, Cai, Xinyu, Liu, Gejun, Rui, Gang, Hu, Baoshan, Shi, Pingfang, Chen, Hua, Wang, Te, Wang, Qingqing, Xie, Linzhen, Xie, Huanguang, Mutanda, Tony, Ntuulo, Juliet, Lubega, Flavia, Tracy, Gayita Teddy, Zaitun, Kayondo, Ndayisaba, Sylvester, Amone, Titus, Odong, Samuel Remmy, Lutomia, Mark, Okatch, Caesar, Bitok, Thomas, Kiambuthi, Alexander, Otsyeno, Fred Mathew Toboso, Jani, Pankaj G, Mutiso, Vincent Muoki, Ating'a, John EO, Kilonzo, Peter Kavoo, Muoki, James, Mbogori, Makena, Wambugu, Joan Wambui, Torutt, Dorothy, Odok, Christopher, Ngetich, Elisha, Otsyeno, Dean, Wakhayanga, Juma, Nzioka, Desmond, Owende, Deogracia, Lucinde, Ruth, Kariuki, Brian Ngure, Kinyua, Dennis, Kamau, Maureen, Mwancha, Maureen, Murgor, Mellany, Nyabuti, Marilyn, Njoki, Rita, Wanza, Patricia, Odongo, Abraham, Marealle, Paul, Wanini, Athman, Elisha, Marwa, Zumbulu, Damas, Godfrey, Pariyo Bonane, Ndeleva, Benjamin Mukulu, Johnson, Murila, Kimani, Moses, Gichui, Kinuthia, Temu, Rogers Joachin, Mselle, Angela Neofitus, Kimario, Ancelimu Rafael, Ramokgopa, Mmampapatla Thomas, Firth, Gregory, Biscardi, Anna Grisillo, Poopedi, Machuene Ananias, Moolman, Johan, Milner, Brenda, Maluleke, Matimba, Jingo, Maxwell, van Deventer, Susan, Pikor, Timothy, Bhaga, Ravi, Mara, Michael, Mwangi, Geoffrey Chege, Maina, Anthony Muchiri, Gicheru, David Wamae, Mwangi, Carol, Wangai, Isaac Kingori, Maina, Peter Watson, Kiptoo, Ezra Mitei, Temiloluwa, Olufemi Olukemi, Ikechukwu, Adeyeye Adeolu, Olugbenga, Ige Oluwole, Bamidele, Ojodu Ishaq, Akanbi, Oladimeji Oladipupo, Subramanian, Panchu, Mosweu, Olivia L, Hailu, Samuel, Tessema, Geletaw, Bezabih, Bahiru, Ayana, Birhanu, Hailu, Hiwot, Zewdneh, Betelhem, Tesfaye, Hana, Tadesse, Sosena, Konadu-Yeboah, Dominic, Ativor, Vincent, Konadu, Peter, Awariyah, Dominic, Quartey, Raphael, Kumah-Ametepey, Raphael, Saani, Osman, Quansah, Robert Ekow, Baidoo, Paa Kwesi, Trafton, Peter, Anyitey-Korkor, David, Leat, Michael, Sobotie, Johnny, Opuni, Godwin, Kusi, Kwasi, Baah, Twimasi, Okyere, Paul, Mensah, Bernice, Sarpong, Doris Akuoko, Agbenorwu, Felicia, Osei-Donkor, Phyllis, Opoku, Priscilla, Segbefia, Michael, Oguzie, Gerald Chukwuemeka, Iyidobi, Emmanuel Chino, Nwadinigwe, Cajetan Uwatoronye, Oguzie, Sharon Amarachi Uloma, Kesiena, Emina Bami, Ndasi, Henry Tanyi, Ghislain, Nietiayurk Aminake, Shey, Mala Irine, Nanje, Ikose John, Shyam, Ashok, Borate, Madhav, Patil, Sampat Dumbre, Karkamakar, Sachin, Patil, Shailesh, Ranaware, Abhijeet, Tamboli, Shadab, Gandhalikar, Manish, Tupe, Rohini, Chaudhari, Vishal, Joshi, Avanti, Patil, Sanjay, Dalwekar, Mohit Madhukar, Gandhi, Tejas, Latkar, Chintamani, Pundkare, Gopal, Shrivastava, Sandeep, Singh, Pradeep K, Deshpande, Sanjay, Baheti, Sumit, Mittal, Ravi, Sharma, Vijay, Cherian, Vinoo Mathew, Jepegnanam, Thilak Samuel, Titus, Vijay T K, Nithyananth, Manasseh, Boopalan, Palapattu R J V C, Varghese, Viju Daniel, Arockiaraj, Justin, Mahajan, Anupam, John, Bobby, Pandey, Ritesh, Prakash, Jeewan S, Abraham, Valsamma, Rajkumar, Arti, Chhabra, Harvinder Singh, Sharawat, Rajesh, Kumar, Ritabh, Chawla, Pushkar, Yadav, Rashmi, Iyer, Rajagopalan N, Nair, Naveen, Amaravathi, Rajkumar S, Santhanagopa, Srinivasalu, Pilar, Anoop, Tamboowala, Keith Behram, Dhillon, Mandeep S, Dhatt, Sarvdeep S, Chase, Asolie, Bhavsar, Neel M, Musa, Rameez, Shah, Darshan, Chodavadiyah, Sunil, Patel, Pankaj G, Qadir, Raja Irfan, Bukhari, Syed Imran, Baz, Khushnood Ali, Byanjankar, Subin, Joshi, Ruban Raj, Dwivedi, Rajeev, Sharma, Jay Raj, Quang, La Ngoc, Chinh, Nguyen Duc, Hong, Vu Bao, Sa-ngasoongsong, Paphon, Kulachote, Noratep, Sirisreetreerux, Norachart, Pongsamakthai, Wanjak, Tabu, Irewin Alagar, Reyes, Paula Veronica, Caiquep, Iardinne, Bituin, Joni Mitchell Robles, González, Jenna, Golbakhsh, Mohammadreza, Haddadi, Mashyaneh, Saadat, Soheil, Zafarghandi, Mohammadreza, Orozco, Clotilde Fuentes, Ruíz, José de Jesús Martínez, Arreguin, Gustavo Armando Tafoya, Flores, César Eduardo Pinedo, Verduzco, Irydia Guadalupe Pellegrini, Camacho, Miguel Oscar Hernandez, Téllez, Diego Abraham Estrada, López, Rodrigo Salcedo, Navarro, Ileana Guadalupe Canales, Pérez, Mizael Dennis, Carrillo, Daniel de Jesús Enciso, López, Paola Alejandra Álvarez, Gómez, Adán Cervantes, Bravo, Fátima Nohemí Franco, Arias, Eugenia de los Ángeles Reyes, Elguezabal, Igor A. Escalante, Rizzo, Ennio Antonio, Hovsepian, Jean Michel, Rodriguez, Victor, Baldo, Manuel Malaret, Serrano, Andres, Valenciano, Carlos G. Sanchez, Salcedo, Edgar Efren Mercado, Medina, Fryda, Bidolegui, Fernando, Pereira, Sebastian, Aguilar, Gerardo, Rubio-Avila, Jorge, Belangero, William Dias, Mariolani, José Ricardo Lenzi, Livani, Bruno, Lugnani, André, Rossi, Felipe, Katayama, Angela, Baldy, Fernando, de Moraes, Vinícius Ynoe, Fogagnolo, Fabricio, Kojima, Kodi Edson, Silva, Jorge dos Santos, Demange, Marco Kawamura, de Andrade-Silva, Fernando Brandão, da Silva, Adriana Carvalho Gomes, Elias, Nelson, Martinez, Dino Aguilar, Contreras, Fernando, Garuz, Mario, Quintero, Jose Eduardo, Merchan, Gavino, Lurita, Christian M. Lozano, Manrique, Aturo D. Torres, Fernandez, Jorge Hurtado, Vincenti, Sergio Iriarte, Bobarin, Alfredo Pozzo, Sanchez, Dalton Salinas, Altieri, Julio Segovia, Almada, Diego, Bogado, Derlis, Coronel, Carlos, Boveda, Cristian, del Valle, Victor, Montiel, Carlos, Marin, Nelson, Barquet, Antonio, Rienzi, Daniel, Amanquez, Carlos, Beauvoir, Georges, Cutipa, Iván J Salce, Ribeiro, José Eduardo Grandi, Avila, José María Jiménez, Padilla, Luis, Ochoa, Hernando Cuevas, Cano, Hernando Cuevas, González, Adriana Vaca, Gutierrez, Nubia Itzel Gonzalez, Espinola, Victor, Pouramin, Panthea, Busse, Jason W, Devereaux, P J, and Ivers, Rebecca

Published
2020
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36. Living cationic polymerization of styrene monomers

Author

Ma, Yinghua

Subjects
547, Chemical Engineering, Applied Chemistry, Chemical Engineering
Abstract

This thesis describes an experimental investigation of synthesis of polystyrene under various polymerization conditions such as solvent polarity, temperature, initial concentrations of initiator, catalyst, monomer and added salts or co-catalyst, which was achieved using the living cationic polymerization technology in conjunction with gel permeation chromatography (GPC) and NMR spectroscopy. Polymerizations of styrene were conducted using 1-phenyl ethylchloride (1-PEC) as an initiator and tin tetrachloride (SnCI4) as a catalyst in the presence of tetra-n-Butylammonium chloride (nBu4NCI). Effects of solvent polarity varied by mixing dichloromethane (DCM) and less polar cyclohexane (C.hex), temperature, initial concentrations of SnC14, 1-PEC and nBu4NCI on the polymerizations were examined, and the conditions under which a living polymerization can be obtained were optimised as: [styrene]o ~ 0.75 - 2 M; [1-PEC]o ~ 0.005 - 0.05 M; [SnCI4Jo ~ 0.05 - 0.4 M; [nBu4NCIJo ~ 0.001 - 0.1 M; DCM/C.hex ~ 50/0 - 20/30 v/v; T ~ 0 to -45°C. Kinetic studies of styrene polymerization using the Omnifit sampling method showed that the number average molecular weight (Mn) of the polymers obtained increased in direct proportion to monomer conversion and agreed well with the theoretical Mn expected from the concentration ratios of monomer to initiator. The linearities of both the 1n([MJoI[M]) vs. time plot and the Mn vs. monomer conversion plot, and the narrow molecular weight distribution (MWD) measured using GPC demonstrated the livingness of the polymerizations, indicating the absence of irreversible termination and transfer within the lifetimes of the polymerizations. The proposed 'two species' propagation mechanism was found to apply for the styrene polymerization with 1-PEC/SnCI4 in the presence of nBu4NCl. The further kinetic experiments showed that living styrene polymerizations were achieved using the 1-PEC/SnCI4 initiating system in mixtures of DCM/C.hex 30/20 v/v at -15°C in the presence of various bromide salts, tetra-n-butylammonium bromide, tetra-n-pentylammonium bromide, tetra-n-heptylammonium bromide, and tetra-n-octylammonium bromide, respectively. The types of the bromide salts were found to have no significant effect on monomer conversion, Mn, polydispersity and initiation efficiency. Living polymerizations of styrene were also achieved using titanium tetrachloride (TiCI4) as a catalyst and 1-PEC as an initiator in the presence of a small amount of 2,6-di-tert-butylpyridine or pyridine instead of nBu4NCl. GPC analysis showed that the polymers obtained had narrow polydispersities (P.D. < 1.3), and the linearities of both the In([MJo/[MJ) vs. time plot and the Mn vs. monomer conversion plot demonstrated that the polymerizations are living, when the ratio of DCM and C.hex was less than 40 : 10 and the reaction temperature was not lower than -15°C. The reaction orders relative to TiCl4 and 1-PEC were estimated from the investigations into the rate of polymerization to be 2.56 and 1.0 respectively. lH and 13C NMR analysis of the resultant polystyrene would suggest the end-functionality of the product polymers is chlorine for all living polymerizations.

Published
2000
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39. Associations between greenspace surrounding schools and lipid levels in Chinese children and teenagers

Author

Hu, Li-Xin, primary, Fan, Shujun, additional, Ma, Yinghua, additional, Liu, Xiao-Xuan, additional, Bao, Wen-Wen, additional, Guo, Yuming, additional, Hu, Li-Wen, additional, Chen, Gongbo, additional, Zeng, Xiao-Wen, additional, Zou, Zhiyong, additional, Yang, Bo-Yi, additional, Ma, Jun, additional, Yang, Zhicong, additional, Chen, Ya-Jun, additional, and Dong, Guang-Hui, additional

Published
2023
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40. La gare à un mètre

Author

Baron, Nacima and Ma, Yinghua

Subjects
contrôle des foules, mobilité quotidienne, density, capacité d’accueil, crowd control, railway stations, distanciation, espace public, everyday mobility, public space, flux piéton, densité, mass transit, surveillance, carrying capacity, gares, pedestrian flow, transport public
Abstract

Depuis la crise sanitaire, les grandes gares voient leur capacité d’accueil limitée pour respecter la distanciation. Dans les métropoles d’Asie, on mobilise des technologies qui renforcent la surveillance des voyageurs et permettent de respecter une jauge maximale. En France, on tente d’inciter les voyageurs à s’espacer d’eux-mêmes par des moyens moins intrusifs, notamment en réorganisant la signalétique et les protocoles d’embarquement. En comparant ces deux stratégies, on questionne ce que la distanciation fait, ici et là-bas, aux pratiques et aux lieux de mobilité collective et à l’impératif économique de densification dans et autour des gares qui a prévalu jusqu’à présent. Articulant science des flux et régulation sanitaire des lieux du transport, l’article offre une approche comparative transcontinentale, puis interroge le statut des grandes gares comme showroom d’un nouvel urbanisme postpandémique. Since the pandemy, the carrying capacity of major railway stations has been restricted to respect the distance. In Asian metropolises, a tech-driven flow management system reinforces the surveillance of travellers and help the maintenance of a top affluence in station’s buildings. In France, an attempt is made to space out travelers with less intrusive processes, such as signage and boarding protocol adaptation. A comparison between these two responses leads us to question what physical distancing does, here and there, to the practices and places of transit and to the economic injonction to densify flows in and around stations until now. Articulating the approaches of crowding science and health regulation in transit environments, the article presents a transcontinental comparison, and then questions the status of major station as post pandemic urbanism showroom.

Published
2023

41. Learning Automata Based Cooperative Student-Team in Tutorial-Like System

Author

Wang, Yifan, Jiang, Wen, Ma, Yinghua, Ge, Hao, Jing, Yuchun, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Kobsa, Alfred, editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Weikum, Gerhard, editor, Goebel, Randy, editor, Tanaka, Yuzuru, editor, Wahlster, Wolfgang, editor, Siekmann, Jörg, editor, Huang, De-Shuang, editor, Jo, Kang-Hyun, editor, and Wang, Ling, editor

Published
2014
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