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A novel AIE supramolecular polymer (BPK) was synthesized by bis(2-hydroxy-1-naphthaldehyde) terephthalo hydrazone functionalized pillar [5]arene and cross-linked using a bis(4.4-dipyridinium salt)cross-linker via host-guest complexation. BPK exhibited strong aggregation-induced emission (AIE) in binary solutions of DMSO/H 2 O. BPK could be an AIE-based sensor with specific fluorescence sensing ability for L-Arg in water. The detection limit of BPK for L-Arg was 3.95 × 10−7 M, and other amino acids did not interfere with the sensing process. Moreover, in a pure DMSO solvent, BPK can self-assemble into a fibrous structure of the right-hand spiral by guest-induced supramolecular helices. At 80 % water content, BPK undergoes a morphological transformation into supramolecular polymer. Intriguingly, BPK exhibits a reversible transformation from a polymer to a nanosphere through the alternating addition of trifluoroacetic acid and arginine. Additionally, the fluorescence of BPK demonstrates an "on-off" switch. This phenomenon is attributed to the formation and disruption of intermolecular hydrogen bonds. The reversible manipulation of polymer materials' morphology and optical properties holds significant potential in biomedicine and smart materials. An efficient guest-induced supramolecular helix was developed for the simultaneous detection of amino acids and precise morphology control by amino acids. [Display omitted] • In this study, a novel AIE supramolecular polymer was constructed by host-guest interaction. • We have constructed a highly sensitive sensing platform for arginine through multi-hydrogen bonding interactions. • We have achieved precise modulation of the morphology of supramolecular polymers by alternating adding L-Arg and TFA. • We report a novel supramolecular helical structure that can be realized by adding a guest K to the host BP. [ABSTRACT FROM AUTHOR]

Background/Purpose: Although exhaustively studied, the mechanism responsible for tooth support and the mechanical properties of the periodontal ligament (PDL) remain a subject of considerable controversy. In the past, various experimental techniques and theoretical analyses have been employed to tackle this intricate problem. The aim of this study was to investigate the viscoelastic behaviors of the PDL using three-dimensional finite element analysis. Methods: Three dentoalveolar complex models were established to simulate the tissue behaviors of the PDL: (1) deviatoric viscoelastic model; (2) volumetric viscoelastic model; and (3) tension-compression volumetric viscoelastic model. These modified models took into consideration the presence of tension and compression along the PDL during both loading and unloading. The inverse parameter identification process was developed to determine the mechanical properties of the PDL from the results of previously reported in vitro and in vivo experiments. Results: The results suggest that the tension-compression volumetric viscoelastic model is a good approximation of normal PDL behavior during the loading-unloading process, and the deviatoric viscoelastic model is a good representation of how a damaged PDL behaves under loading conditions. Moreover, fluid appears to be the main creep source in the PDL. Conclusion: We believe that the biomechanical properties of the PDL established via retrograde calculation in this study can lead to the construction of more accurate extra-oral models and a comprehensive understanding of the biomechanical behavior of the PDL. [ABSTRACT FROM AUTHOR]

The morbidity and mortality of lung cancer are increasing. The Corona Virus Disease 2019 (COVID-19) is caused by novel coronavirus 2019-nCoV-2, leading to subsequent pulmonary interstitial fibrosis with chronic inflammatory changes, e.g., inflammatory factors repeatedly continuously stimulating and attacking the alveolar epithelial cells. Meanwhile, 2019-nCoV-2 can activate PI3K/Akt and ERK signaling pathways, which can play the double roles as both anti-inflammatory and carcinogenic factors. Moreover, hypoxemia may be developed, resulting in the up-regulation of HIF-1 α expression, which can be involved in the occurrence, angiogenesis, invasion and metastasis of lung cancer. Additionally, the immune system in 2019-nCoV-2 infected cases can be suppressed to cause tumor immune evasion. Therefore, we speculate that COVID-19 may be a risk factor of secondary lung cancer. [ABSTRACT FROM AUTHOR]

Summary Objective To clarify whether exanthema is related to illness severity in acute enterovirus infection in children. Methods The data of pediatric inpatients at Zhujiang Hospital during 2009–2012 with an acute enterovirus infection were reviewed retrospectively. Enterovirus infection was determined by real-time reverse transcription PCR. Clinical data were summarized and compared between cases with and without exanthema. Results A total of 780 pediatric inpatients with an acute enterovirus infection were included in this study, of whom 83 (10.6%) presented no exanthema. The percentage of deaths in the group of patients without exanthema was significantly higher than that in the group with exanthema (7.2% vs. 1.1%; p = 0.002). Central nervous system involvement (41.0% vs. 30.0%; p = 0.041), severe central nervous system (CNS) involvement (21.7% vs. 11.0%; p = 0.005), severe CNS involvement with cardiopulmonary failure (9.6% vs. 2.3%; p = 0.002), an altered level of consciousness (15.7% vs. 7.6%; p = 0.013), and convulsions (14.4% vs. 6.3%; p = 0.007) occurred significantly more frequently in the group without exanthema. Conclusions A considerable proportion of children with an acute enterovirus infection in Guangdong Province, China during 2009–2012 presented no exanthema, and the absence of exanthema was found to be related to death and illness severity for these acute enterovirus infections. Clinicians in China should consider enterovirus as the possible pathogen when treating children with an acute pathogen infection without exanthema. [ABSTRACT FROM AUTHOR]