When R is sufficiently electron withdrawing, the fluorine in the R-F molecules could interact with electron donors (e.g., ammonia) and form a noncovalent bond (F⋅⋅⋅N). Although these interactions are usually categorized as halogen bonding, our studies show that there are fundamental differences between these interactions and halogen bonds. Although the anisotropic distribution of electronic charge around a halogen is responsible for halogen bond formations, the electronic charge around the fluorine in these molecules is spherical. According to source function analysis, F is the sink of electron density at the F⋅⋅⋅N BCP, whereas other halogens are the source. In contrast to halogen bonds, the F⋅⋅⋅N interactions cannot be regarded as lump-hole interactions; there is no hole in the valence shell charge concentration (VSCC) of fluorine. Although the quadruple moment of Cl and Br is mainly responsible for the existence of σ-holes, it is negligibly small in the fluorine. Here, the atomic dipole moment of F plays a stabilizing role in the formation of F⋅⋅⋅N bonds. Interacting quantum atoms (IQA) analysis indicates that the interaction between halogen and nitrogen in the halogen bonds is attractive, whereas it is repulsive in the F⋅⋅⋅N interactions. Virial-based atomic energies show that the fluorine, in contrast to Cl and Br, stabilize upon complex formation. According to these differences, it seems that the F⋅⋅⋅N interactions should be referred to as "fluorine bond" instead of halogen bond.
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http://dx.doi.org/10.1002/chem.201405054 | DOI Listing |
Int J Surg
January 2025
Department of Cardiovascular Surgery, Xijing Hospital, Xi'an, Shaanxi, China.
Background: The impact of aortic arch (AA) morphology on the management of the procedural details and the clinical outcomes of the transfemoral artery (TF)-transcatheter aortic valve replacement (TAVR) has not been evaluated. The goal of this study was to evaluate the AA morphology of patients who had TF-TAVR using an artificial intelligence algorithm and then to evaluate its predictive value for clinical outcomes.
Materials And Methods: A total of 1480 consecutive patients undergoing TF-TAVR using a new-generation transcatheter heart valve at 12 institutes were included in this retrospective study.
J Phys Chem Lett
January 2025
State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China.
The Ni-N(His) coordination bond, formed between the nickel ion and histidine residues, is essential for recombinant protein purification, especially in Ni-NTA-based systems for selectively binding polyhistidine-tagged (Histag) proteins. While previous studies have explored its bond strength in a synthetic Ni-NTA-Histag system, the influence of the surrounding protein structure remains less understood. In this study, we used atomic force microscopy-based single-molecule force spectroscopy (AFM-SMFS) to quantify the Ni-N(His) bond strength in calprotectin, a biologically relevant protein system.
View Article and Find Full Text PDFInt J Surg
January 2025
Department of Anesthesiology, Jiangxi Cancer Hospital & Institute, Jiangxi Clinical Research Center for Cancer, The Second Affiliated Hospital of Nanchang Medical College, Jiangxi Key Laboratory of Oncology, Nanchang, Jiangxi Province, China.
Nerve growth factor (NGF) is critical in regulating the homeostasis of microglial cells. It activates various signaling pathways that mediate the phosphorylation of cAMP response element-binding protein (CREB) at key regulatory sites. The decrease in phosphorylated CREB (p-CREB) expression is linked to neuroinflammatory responses.
View Article and Find Full Text PDFCurr Opin Crit Care
January 2025
Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS).
Purpose Of Review: This narrative review discusses the mechanisms connecting gut dysbiosis to adverse clinical outcomes in critically ill patients and explores potential therapeutic strategies.
Recent Findings: In recent years, the study of microbiota in ICUs has gained attention because of its potential effects on patient outcomes. Critically ill patients often face severe conditions, which can compromise their immune systems and lead to opportunistic infections from bacteria typically harmless to healthy individuals.
ACS Nano
January 2025
Department of Infectious Diseases, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China.
Nonantibiotic strategies are urgently needed to treat acute drug-resistant bacterial pneumonia. Recently, nanomaterial-mediated bacterial cuproptosis has arisen widespread interest due to its superiority against antibiotic resistance. However, it may also cause indiscriminate and irreversible damage to healthy cells.
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