作者机构：
[Yu, Miao; Guo, Xin; Zhang, Kai] Sichuan Univ, Sch Mech Engn, Chengdu 610065, Peoples R China.;[Yu, Miao; Guo, Xin; Zhang, Kai] Sichuan Univ, Yibin Ind Technol Res Inst, Yibin 644000, Peoples R China.;[Kang, Xiaomin] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;[Zhang, Song] Moutai Inst, Dept Food Sci & Engn, Renhuai 564502, Guizhou, Peoples R China.;[Qian, Lu; Qian, L] South China Univ Technol, Sch Mat Sci & Engn, Guangzhou 510641, Peoples R China.
通讯机构：
[Zhang, S ] M;[Qian, L ] S;Moutai Inst, Dept Food Sci & Engn, Renhuai 564502, Guizhou, Peoples R China.;South China Univ Technol, Sch Mat Sci & Engn, Guangzhou 510641, Peoples R China.
摘要：
Hyaluronic acid (HA), a vital glycosaminoglycan in living organisms, possesses remarkable mechanical and viscoelastic properties that have garnered significant attention in therapeutic, biomedical, and cosmetic applications. However, a comprehensive picture of the physicochemical and biocharacterization of HA at the single-molecule level remains elusive. In this work, atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS) and molecular dynamics (MD) simulation were used to investigate the nanomechanics and water retention properties of HA at the single-molecule level. The present study aims to unravel the intricate details of the influence of molecular structure on HA behavior and shed light on its unique attributes. According to the force measurements, the energy used to stretch a HA chain in water is 8.45 kJ/mol, significantly surpassing that of Curdlan (3.45 kJ/mol) and chitin (2.23 kJ/mol), both of which possess molecular structures partially similar to that of HA. Intriguingly, the strength of the intrachain interaction of HA (5.54 kJ/mol) was considerably weaker compared to Curdlan (11.06 kJ/mol) and chitin (or cellulose, 10.76 kJ/mol). This result indicates that HA exhibits a preference for interacting with water rather than with itself, thereby showing enhanced water affinity. Moreover, the force measurements demonstrated that changing the glycosidic bond from β-(1-3) (Curdlan) or β-(1-4) (chitin or cellulose) to β-(1-3) + β-(1-4) (HA) resulted in polysaccharides displaying improved water affinity and more extended conformation. These conclusions were further verified by molecular dynamics (MD) simulations. Overall, our work sheds new light on the nanomechanics and water retention properties of HA at the single-molecule level, offering valuable insights for future research in this field.
作者机构：
[Gao, Beibei; Cai, Tao; Tan, Jing; Zhang, Qingyan; Zeng, Qingyi] Univ South China, Sch Resources & Environm & Safety Engn, Hengyang 421001, Hunan, Peoples R China.;[Liu, Yi-Lin] Univ South China, Coll Mech Engn, Hengyang 421001, Hunan, Peoples R China.;[Chang, Sheng] Nanjing Univ Aeronaut & Astronaut, Sch Energy & Power Engn, Nanjing 210016, Jiangsu, Peoples R China.;[Zhao, Shuaifei] Deakin Univ, Inst Frontier Mat IFM, Geelong, Vic 3216, Australia.;[Wu, Suqing] Wenzhou Univ, Coll Life & Environm Sci, Natl & Local Joint Engn Res Ctr Ecol Treatment Tec, Key Lab Zhejiang Prov Water Environm & Marine Biol, Wenzhou 325000, Peoples R China.
通讯机构：
[Qingyi Zeng] S;[Yi-Lin Liu] C;College of Mechanical Engineering, University of South China, Hengyang, Hunan, 421001, China<&wdkj&>School of Resources & Environment and Safety Engineering, University of South China, Hengyang, Hunan, 421001, China
摘要：
A cobalt (Co)-doped perovskite molybdenum trioxide (alpha-MoO3) catalyst (Co-MO) was synthesized by a facile pyrolysis strategy and used for degrading various organic contaminants via peroxymonosulfate (PMS) activation. The doped Co was inserted in the inter space between the octahedron [MoO6], facilitating the growth of the alpha-MoO3 crystal on the [010] direction. This unique structure accelerated the activation of PMS as the Co-MO could function as a carrier for electron transfer to facilitate the Co(II)/Co(III) cycle in the Co-MO/PMS sys-tem. As a result, the Co-MO/PMS system showed noticeable activity for removing 100% bisphenol A (BPA) under a broad conditions within 30 min. The radical quenching test and electron paramagnetic resonance analysis revealed that singlet oxygen (1O2) was the main active species for BPA degradation in the Co-MO/PMS system, while free radicals, such as O2 center dot-, SO4 center dot-and center dot OH, were also produced as the intermediate species. Furthermore, the carrier mechanism may enable the Co-MO/PMS system maintain relatively high performance during repeat use, and also excellent adaptability was revealed by the well function in various water matrices and high activity in degrading various refractory organic pollutants. Our findings pave a useful avenue for the rational design of novel cobalt-doped catalysts with high catalytic performance toward wide environmental applications.
作者机构：
[Hou, Wei; Wang, Hongqiang; Wang, Qingliang; Li, Hui; Zhang, Rui; Hu, Eming; Lei, Zhiwu] Univ South China, Sch Resource & Environm & Safety Engn, Hengyang 421001, Peoples R China.;[Hou, Wei; Wang, Qingliang] Univ South China, Cooperat Innovat Ctr Nucl Fuel Cycle Technol & Eq, Hengyang 421001, Peoples R China.;[Wang, Hongqiang] Univ South China, Hengyang Key Lab Soil Pollut Control & Remediat, Hengyang 421001, Peoples R China.;[Wang, Qingliang; Hu, Eming; Lei, Zhiwu] Univ South China, Hunan Key Lab Rare Met Minerals Exploitat & Geol, Hengyang 421001, Peoples R China.
通讯机构：
[Qingliang Wang] S;School of Resource & Environment and Safety Engineering, University of South China, Hengyang, 421001, China<&wdkj&>Cooperative Innovation Center for Nuclear Fuel Cycle Technology and Equipment, University of South China, Hengyang, 421001, China<&wdkj&>Hunan Key Laboratory of Rare Metal Minerals Exploitation and Geological Disposal of Wastes, University of South China, Hengyang, 421001, China
作者机构：
[王玥; 代正燕; 李润; Zeng, Guo; 刘丹] Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University, Chengdu 610041, China;[周容] West China Second Hospital, Shichuan University;[刘婧] Chengdu Women's and Children's Central Hospital;[张琚] Sichuan Provincial Maternal and Child Health Hospital;[Zeng, Guo] Email: zgmu2007@126. com
摘要：
Intensity inhomogeneity may cause considerable difficulties in segmentation of CT image. In order to overcome the difficulties caused by intensity inhomogeneity, the region-scalable fitting (RSF) model was put forward. RSF model draws upon intensity information in local regions with a controllable scale. But only using intensity information may lead to slow convergence rate and poor denoise ability. Combining the method of robust statistics, RSF model is improved in this paper. In the improved model, the intensity in RSF model is replaced with local robust statistics which is the weighted combination of inter-quartile range, mean absolute deviation and intensity median in local region. Inter-quartile range and mean absolute deviation in local region are introduced to sharpen object boundaries, and intensity median in local region is introduced to reduce image noise. The contrast experiments between RSF model and the improved model are provided, which demonstrate the fast convergence rate and robustness to noise of the improved model.
