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14. On the classical reaction rate and the first-time problems of Brownian motion

Author

Zhang, Aihua and Choi, Sun

Subjects
Physics - Chemical Physics
Abstract

We have developed efficient techniques to solve the first-time problems of Brownian motion. Based on a time-scale separation of recrossings, we show that Eyring's transmission coefficient ($\kappa$) equals to the one ($\kappa_\mathrm{V}$) corresponding to an absorbing boundary consistent with the transition state theory, which is greater than the one ($\kappa_\mathrm{K}$) derived by Kramers. We also propose methods for reaction rate determination by analyzing short-time trajectories from the barrier maximum, and discuss the relation to the reactive flux method and the significance of reaction coordinates., Comment: 6 pages, 5 figures

Published
2022
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16. Diagnostic and prognostic implications of bacteremia in patients with complicated pleural infection

Author

Kim Chang Ho, Park Ji Eun, Cha Jung Guen, Lim Jae Kwang, Park Jongmin, Lee Yong Hoon, Choi Sun Ha, Seo Hyewon, Yoo Seung Soo, Lee Shin Yup, Cha Seung Ick, Park Jae Yong, and Lee Jaehee

Subjects
pleural infection, empyema, bacteremia, outcome, microbiology, Medicine, Specialties of internal medicine, RC581-951
Abstract

The clinical significance of bacteremia in patients with complicated pleural infection is still uncertain. We aimed to examine the incidence and clinical significance of bacteremia in patients with complicated pleural infection.

Published
2024
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18. GPCR Agonist-to-Antagonist Conversion: Enabling the Design of Nucleoside Functional Switches for the A2A Adenosine Receptor.

Author

Shiriaeva, Anna, Park, Daejin, Kim, Gyudong, Lee, Yoonji, Hou, Xiyan, Jarhad, Dnyandev B, Kim, Gibae, Yu, Jinha, Hyun, Young Eum, Kim, Woomi, Gao, Zhan-Guo, Jacobson, Kenneth A, Han, Gye Won, Stevens, Raymond C, Jeong, Lak Shin, Choi, Sun, and Cherezov, Vadim

Subjects
Thiophenes, Nucleosides, Receptor, Adenosine A2A, Crystallography, X-Ray, Molecular Conformation, Adenosine A2 Receptor Antagonists, Neurosciences, Medicinal and Biomolecular Chemistry, Organic Chemistry, Pharmacology and Pharmaceutical Sciences, Medicinal & Biomolecular Chemistry
Abstract

Modulators of the G protein-coupled A2A adenosine receptor (A2AAR) have been considered promising agents to treat Parkinson's disease, inflammation, cancer, and central nervous system disorders. Herein, we demonstrate that a thiophene modification at the C8 position in the common adenine scaffold converted an A2AAR agonist into an antagonist. We synthesized and characterized a novel A2AAR antagonist, 2 (LJ-4517), with Ki = 18.3 nM. X-ray crystallographic structures of 2 in complex with two thermostabilized A2AAR constructs were solved at 2.05 and 2.80 Å resolutions. In contrast to A2AAR agonists, which simultaneously interact with both Ser2777.42 and His2787.43, 2 only transiently contacts His2787.43, which can be direct or water-mediated. The n-hexynyl group of 2 extends into an A2AAR exosite. Structural analysis revealed that the introduced thiophene modification restricted receptor conformational rearrangements required for subsequent activation. This approach can expand the repertoire of adenosine receptor antagonists that can be designed based on available agonist scaffolds.

Published
2022

39. High-resolution CT phenotypes in pulmonary sarcoidosis: a multinational Delphi consensus study

Author

Anderson, Adam, Morgenthau, Adam, Gaser, Adrian, Vizel, Alexander, Speranskaya, Alexandra, Gerke, Alicia, Goksel, Altinisik, Undurraga, Alvaro, Sharma, Amita, Oh, Andrea, Leung, Ann, Larici, Anna Rita, Prasse, Antje, Mazzei, Antonietta, Morais, Antonio, Bhalla, Ashu, Del Rio, Belen, Jankharia, Bhavin, Elicker, Brett, Pereira, Carlos, Biegelman-Aubry, Catherine, White, Charles, Ravaglia, Claudia, Hsia, Connie, Schaefer-Prokop, Cornelia, Launay, David, Talwar, Deepak, Castillo, Diego, Patel, Divya, Israel-Biet, Dominique, Valeyre, Dominique, Britt, Edward James, Bargagli, Elena, Bendstrup, Elisabeth, Crouser, Elliott, Nossent, Esther, Shmelev, Eugeny, Porquera, Eva Carmona, Bonella, Francesco, Cohen-Aubart, Fleur, Jeny, Florence, Ferrara, Giovanni, Jin, Gong Yong, Robbie, Hasti, Prosch, Helmut, Sumikawa, Hiromitsu, Ling-Pei, Ho, Lee, Ho Yun, Strambu, Irina, Buendia-Roldan, Ivette, Grutters, Jan, Ryu, Jay, Swigris, Jeff, Miedema, Jelle, Goo, Jin Mo, Barnett, Joseph, Verschakelen, Johny, Goldin, Jonathan, Seo, Joon Beom, Enghelmayer, Juan, Mana, Juan, Behr, Juergen, Patterson, Karen, Antoniou, Katerina, Brown, Kevin, Fujimoto, Kiminori, Savale, Laurent, Maier, Lisa, Richeldi, Luca, Neto, Manuel Lessa Ribeiro, Humbert, Marc, Judson, Marc, Veltkamp, Marcel, Wilsher, Margaret, Molina, Maria, Otaola, Maria, Revel, Marie-Pierre, Silva, Mario, Drent, Marjolein, Schiebler, Mark, Wijsenbeek-Lourens, Marlies, Bonifazi, Martina, Remy-Jardin, Martine, Koslow, Matthew, Balter, Meyer, Kreuter, Michael, Thillai, Muhunthan, Hamzeh, Nabeel, Chaudhuri, Nazia, Mogulkoc, Nesrin, Todd, Nevins, Screaton, Nick, Goh, Nicole, Shah, Nirav, Obi, Ogugua, Shlobin, Oksana, Baranova, Olga, Bresser, Paul, Rottoli, Paula, Brillet, Pierre-Yves, Said-Hartley, Qonita, Borie, Raphael, Mostard, Remy, van Zyl-smit, Richard, Kairalla, Ronaldo, Egashira, Ryoko, Boussouar, Samia, Lee, Sang Min, Bhalla, Sanjeev, Tomassetti, Sara, Quadrelli, Silvia, Hart, Simon P, Danoff, Sonye, Rajan, Sujeet, Choi, Sun Mi, Copley, Susan, Kim, Tae Jung, Johkoh, Takeshi, Corte, Tamera, McLoud, Theresa, Wessendorf, Thomas, Alfaro, Tiago, Arai, Toru, Costabel, Ulrich, Vicens-Zygmunt, Vanesa, Poletti, Venerino, Cottin, Vincent, Vucinic, Violeta, Wuyts, Wim, van Es, Wouter, Jeong, Yeon Joo, Inoue, Yoshikazu, Desai, Sujal R, Sivarasan, Nishanth, Johannson, Kerri A, George, Peter M, Culver, Daniel A, Devaraj, Anand, Lynch, David A, Milne, David, Renzoni, Elisabetta, Nunes, Hilario, Sverzellati, Nicola, Spagnolo, Paolo, Baughman, Robert P, Yadav, Ruchi, Piciucchi, Sara, Walsh, Simon L F, Kouranos, Vasileios, and Wells, Athol U

Published
2024
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49. Medicating the coast in a metropolitan city: Enantiomeric profiles and joint probabilistic risk assessment of antidepressants and antihistamines

Author

Rongben Wu, Esther Yan-yin Sin, Kai Zhang, Shaopeng Xu, Yuefei Ruan, Yim Ling Mak, Ying-kit Yung, Sunny Wai-choi Sun, Rong Yang, and Paul K.S. Lam

Subjects
Urban water system, Stormwater, Joint probabilistic curve, Chiral, Pharmaceutical, Fluoxetine, Environmental sciences, GE1-350
Abstract

Pharmaceuticals are receiving increasing attention as emerging contaminants in the aquatic environment. Herein, we investigated the occurrence of 11 antidepressants, 6 antihistamines and 4 metabolites in treated wastewater effluents, rivers, stormwater, and seawater in Hong Kong, with special focus on chirality. The average levels of ∑pharmaceuticals ranged from 0.525 to 1070 ng/L in all samples and the total annual mass load of target pharmaceuticals in the marine environment of Hong Kong was 756 kg/y. Antihistamines accounted for >80 % of ∑pharmaceuticals, with diphenhydramine and fexofenadine being predominant. The occurrence and enantiomeric profiles of brompheniramine and promethazine sulfoxide were reported in global natural waters for the first time. Among chiral pharmaceuticals, mirtazapine and fexofenadine exhibited R-preference, while others mostly exhibited S-preference, implying that the ecological risks derived from achiral data for chiral pharmaceuticals may be biased. The joint probabilistic risk assessment of fluoxetine revealed that R-fluoxetine and rac-fluoxetine presented different ecological risks from that of S-fluoxetine; Such assessment also revealed that target pharmaceuticals posed only minimal to low risks, except that diphenhydramine posed an intermediate risk. As estimated, 10 % aquatic species will be affected when the environmental level of diphenhydramine exceeds 7.40 ng/L, which was seen in 46.9 % samples. Collectively, this study highlights further investigations on the enantioselectivity of chiral pharmaceuticals, particularly on environmental behavior and ecotoxicity using local aquatic species as target organisms.

Published
2024
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50. Flocking formation and stabilizer of boosted cooperative control on a sphere

Author

Choi, Sun-Ho, Kwon, Dohyun, and Seo, Hyowon

Subjects
Mathematics - Dynamical Systems, Mathematics - Optimization and Control
Abstract

The purpose of this paper is to consider flocking formations of a second order dynamic system on a sphere with a Cucker-Smale type flocking operator and cooperative control. The flocking operator consists of a weighted control parameter and a natural relative velocity. The cooperative control law is given by a combination of attractive and repulsive forces. We prove that the solution to this system converges to an asymptotic spherical configuration depending on the control parameters of the cooperative control law. All possible asymptotic configurations for this system are classified and sufficient conditions for rendezvous, deployment, and local deployment, respectively, are presented. In addition, we provide several numerical simulations to confirm our analytic results. We numerically verify that the solution to this system converges to a formation flight with a nonzero constant speed if we add a boost term. The flocking operator acts as a stabilizer on the spherical cooperative control laws.

Published
2021

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