ABSTRACT
The direct application of liquid marbles in electromagnetic wave (EMW) absorption is challenging due to their poor stability, susceptibility to gravitational collapse, and shaping difficulties. To address this issue, a novel strategy is proposed to incorporate liquid marble microstructures (NaCl/nano-SiO2) encapsulated in organic phases (Octadecane) into the rubber-matrix (SEBS) using the ultrasound-assisted emulsion blending method. The resulting NaCl/SiO2/Octadecane microstructures anchored to SEBS offer a substantial solid-liquid interface consisting of NaCl solution and SiO2. When subjected to an alternating electromagnetic (EM) field, the water molecules and polysorbate within SiO2 exhibit heightened responsiveness to the EM field, and the movement of Na+ and Cl- within these microstructures leads to their accumulation at the solid-liquid interface, creating an asymmetric ion distribution. This phenomenon facilitates enhanced interfacial polarization, thereby contributing to the material's EMW absorption properties. Notably, the latex with 16 wt% SEBS (E-3), exhibiting a surface morphology similar to human cell tissues, achieves complete absorption of X-band (fE = 4.20 GHz, RLmin = -33.87 dB). Moreover, the latex demonstrates light density (0.78 g cm-3) and environmental stability. This study not only highlights the predominant loss mechanism in rubber-based wave-absorbing materials but also provides valuable insights into the design of multifunctional wave-absorbing materials.
ABSTRACT
Glycerol dehydratase is the key and rate-limiting enzyme in the 1,3-propanediol synthesis pathway of Klebsiella pneumoniae, which determined the producing rate and yield of 1,3-propanediol. However, the expression regulation mechanism of glycerol dehydratase gene dhaB remains poorly unknown. In this study, a histone-like nucleoid-structuring (H-NS) protein was identified and characterized as the positive transcription regulator for dhaB expression in K. pneumoniae 2e, which exhibited high tolerance against crude glycerol in our previous study. Deletion of hns gene significantly decreased the transcription level of dhaB in K. pneumoniae 2e, which led to a remarkable defect on strain growth, glycerol dehydratase activity, and 3-hydroxypropanal production during glycerol fermentation. The transcription level of dhaB was significantly up-regulated in crude glycerol relative to pure glycerol, while the inactivation of H-NS resulted in more negative effect for transcription level of dhaB in the former. Though the H-NS expression level was almost comparable in both substrates, its multimer state was reduced in crude glycerol relative to pure glycerol, suggesting that the oligomerization state of H-NS might have contributed for positive regulation of dhaB expression. Furthermore, electrophoretic mobility shift and DNase I footprinting assays showed that H-NS could directly bind to the upstream promoter region of dhaB by recognizing the AT-rich region. These findings provided new insight into the transcriptional regulation mechanism of H-NS for glycerol dehydratase expression in K. pneumoniae, which might offer new target for engineering bacteria to industrially produce 1,3-propanediol.IMPORTANCEThe biological production of 1,3-propanediol from glycerol by microbial fermentation shows great promising prospect on industrial application. Glycerol dehydratase catalyzes the penultimate step in glycerol metabolism and is regarded as one of the key and rate-limiting enzymes for 1,3-propanediol production. H-NS was reported as a pleiotropic modulator with negative effects on gene expression in most studies. Here, we reported for the first time that the expression of glycerol dehydratase gene is positively regulated by the H-NS. The results provide insight into a novel molecular mechanism of H-NS for positive regulation of glycerol dehydratase gene expression in K. pneumoniae, which holds promising potential for facilitating construction of engineering highly efficient 1,3-propanediol-producing strains.
Subject(s)
Bacterial Proteins , Gene Expression Regulation, Bacterial , Glycerol , Hydro-Lyases , Klebsiella pneumoniae , Propylene Glycols , Klebsiella pneumoniae/genetics , Klebsiella pneumoniae/enzymology , Klebsiella pneumoniae/metabolism , Hydro-Lyases/genetics , Hydro-Lyases/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Glycerol/metabolism , Propylene Glycols/metabolism , Promoter Regions, Genetic , FermentationABSTRACT
This study elucidates the mechanisms and principles governing chemoselectivity in synthesizing two distinct N-heterocycles, benzimidazole thiazine and benzothiazole imidazole, through BF3â¢OEt2-catalyzed cyclization reactions of propargyl alcohols with benzimidazole thiols. Employing density functional theory calculations, we highlight the crucial role of fluorine source in influencing chemoselectivity. In DCM, BF3, as the catalytic center, coordinates with propargyl alcohol's hydroxyl group to form a precursor. Conversely, in DMF, [BF2â¢DMF]+, formed from DMF and BF3â¢OEt2, acts as the catalytic center, activating the propargyl alcohol's hydroxyl group. The mechanisms in both solvents involve sequential steps: B-O bond formation, C-O bond cleavage, S-C bond formation, hydrogen atom transfer (HAT), cyclization, and deprotonation. A notable difference is the HAT process: in DCM, it follows a 1,5-HAT process, while in DMF, BF4- formation from DMF and BF3â¢OEt2 provides a fluorine source and introduces steric hindrance, favoring a 1,6-HAT process and leading to unique chemoselectivity. This pioneering research showcases the impact of DMF on cyclization reactions, offering valuable insights for comprehending and designing reactions driven by fluorine sources. Crucially, our results propose an innovative reaction mechanism featuring lower potential energy surfaces, enhancing our understanding of the intricate interplay among reactants, catalysts, and solvents.
ABSTRACT
Adult stem cells, present in various parts of the human body, are undifferentiated cells that can proliferate and differentiate to replace dying cells within tissues. Stem cells have specifically been identified in the cornea, trabecular meshwork, crystalline lens, iris, ciliary body, retina, choroid, sclera, conjunctiva, eyelid, lacrimal gland, and orbital fat. The identification of ocular stem cells broadens the potential therapeutic strategies for untreatable eye diseases. Currently, stem cell transplantation for corneal and conjunctival diseases remains the most common stem cell-based therapy in ocular clinical management. Lens epithelial stem cells have been applied in the treatment of paediatric cataracts. Several early-phase clinical trials for corneal and retinal regeneration using ocular stem cells are also underway. Extensive preclinical studies using ocular stem cells have been conducted, showing encouraging outcomes. Ocular stem cells currently demonstrate great promise in potential treatments of eye diseases. In this review, we focus on the identification, characterisation, and therapeutic application of adult stem cells in the eye.
Subject(s)
Adult Stem Cells , Eye Diseases , Lens, Crystalline , Humans , Child , Retina , Lens, Crystalline/chemistry , Cornea , Eye Diseases/therapy , EyelidsABSTRACT
Polyhexamethylene guanidine (PHMG) is manufactured and applied extensively due to its superior disinfectant capabilities. However, the inhalatory exposure to PHMG aerosols is increasingly recognized as a potential instigator of pulmonary fibrosis, prompting an urgent call for elucidation of the underlying pathophysiological mechanisms. Within this context, alveolar macrophages play a pivotal role in the primary immune defense in the respiratory tract. Dysregulated lipid metabolism within alveolar macrophages leads to the accumulation of foam cells, a process that is intimately linked with the pathogenesis of pulmonary fibrosis. Therefore, this study examines PHMG's effects on alveolar macrophage foaminess and its underlying mechanisms. We conducted a 3-week inhalation exposure followed by a 3-week recovery period in C57BL/6 J mice using a whole-body exposure system equipped with a disinfection aerosol generator (WESDAG). The presence of lipid-laden alveolar macrophages and downregulation of pulmonary tissue lipid transport proteins ABCA1 and ABCG1 were observed in mice. In cell culture models involving lipid-loaded macrophages, we demonstrated that PHMG promotes foam cell formation by inhibiting lipid efflux in mouse alveolar macrophages. Furthermore, PHMG-induced foam cells were found to promote an increase in the release of TGF-ß1, fibronectin deposition, and collagen remodeling. In vivo interventions were subsequently implemented on mice exposed to PHMG aerosols, aiming to restore macrophage lipid efflux function. Remarkably, this intervention demonstrated the potential to retard the progression of pulmonary fibrosis. In conclusion, this study underscores the pivotal role of macrophage foaming in the pathogenesis of PHMG disinfectants-induced pulmonary fibrosis. Moreover, it provides compelling evidence to suggest that the regulation of macrophage efflux function holds promise for mitigating the progression of pulmonary fibrosis, thereby offering novel insights into the mechanisms underlying inhaled PHMG disinfectants-induced pulmonary fibrosis.
Subject(s)
Disinfectants , Pulmonary Fibrosis , Mice , Animals , Pulmonary Fibrosis/metabolism , Guanidine/toxicity , Guanidine/metabolism , Mice, Inbred C57BL , Respiratory Aerosols and Droplets , Lung , Guanidines/metabolism , Macrophages , Disinfectants/pharmacology , LipidsABSTRACT
PURPOSE: This study aimed to create a preoperative risk assessment form for COVID-19-positive hepatobiliary patients to guide further prevention of complications after surgery and reduce morbidity and mortality. DESIGN: Based on the literature, focus groups, and case studies, a multidisciplinary panel of 15 experts conducted three rounds of a Delphi study that resulted in the development of a preoperative risk assessment form to be used by healthcare professionals in the treatment of COVID-19-positive hepatobiliary patients. METHODS: A preoperative risk assessment form for health professionals to use among COVID-19-positive hepatobiliary patients was developed based on literature, focus groups, and case studies. A 3-round Delphi study was conducted to validate and revise the risk assessment form using a multidisciplinary panel of 15 experts involved in hepatobiliary surgery. FINDINGS: The experts demonstrated high cooperation and familiarity with the research topic, with positive coefficients ranging from 93.33% to 100% and authority coefficients ranging from 0.83 to 0.86. The coordination coefficients were 0.33, 0.26, and 0.22, respectively, indicating good coordination among expert opinions. The final risk assessment form included 9 primary (first-level) indicators, 38 secondary (second-level) indicators, and 122 tertiary (third-level) indicators. CONCLUSIONS: The preoperative risk assessment form for hepatobiliary surgery patients infected with COVID-19 is scientifically rigorous, reliable, and valid. This screening tool may be used by health providers to identify high-risk patients, prevent postoperative complications, and reduce morbidity and mortality.
ABSTRACT
In recent years, the neural implicit surface has emerged as a powerful representation for multi-view surface reconstruction due to its simplicity and state-of-the-art performance. However, reconstructing smooth and detailed surfaces in indoor scenes from multi-view images presents unique challenges. Indoor scenes typically contain large texture-less regions, making the photometric loss unreliable for optimizing the implicit surface. Previous work utilizes monocular geometry priors to improve the reconstruction in indoor scenes. However, monocular priors often contain substantial errors in thin structure regions due to domain gaps and the inherent inconsistencies when derived independently from different views. This paper presents DebSDF to address these challenges, focusing on the utilization of uncertainty in monocular priors and the bias in SDF-based volume rendering. We propose an uncertainty modeling technique that associates larger uncertainties with larger errors in the monocular priors. High-uncertainty priors are then excluded from optimization to prevent bias. This uncertainty measure also informs an importance-guided ray sampling and adaptive smoothness regularization, enhancing the learning of fine structures. We further introduce a bias-aware signed distance function to density transformation that takes into account the curvature and the angle between the view direction and the SDF normals to reconstruct fine details better. Our approach has been validated through extensive experiments on several challenging datasets, demonstrating improved qualitative and quantitative results in reconstructing thin structures in indoor scenes, thereby outperforming previous work.
ABSTRACT
Background: Macrophages play a pivotal role in the research landscape of non-small cell lung cancer (NSCLC), contributing significantly to understanding tumor progression, treatment resistance, and immunotherapy efficacy. In this study, we utilized bibliometric techniques to analyze shifts in research hotspots and trends within the field, while also forecasting future research directions. These insights aim to offer guidance for both clinical therapeutic interventions and foundational scientific inquiries. Methods: All publications were released between 1993 and 2023 and focus on research pertaining to macrophages in the field of NSCLC. The articles were identified from the Web of Science Core Collection and analyzed using VOSviewer 1.6.19, CiteSpace 6.2.R2, and Scimago Graphica 1.0.35. Result: A total of 361 articles authored by 3,072 researchers from 48 countries were included in the analysis. TAMs have gained increasing attention for their role in NSCLC development and as potential therapeutic targets. Modulating TAM behavior may offer avenues to suppress tumor growth and drug resistance, improving patient outcomes. International collaboration, particularly between China and the United States, accelerates progress in NSCLC research, benefiting patients worldwide. The research hotspot revolves around understanding the role of macrophages in immunotherapy, focusing on their contribution to tumor progression, therapeutic resistance, and potential as therapeutic targets in NSCLC. Conclusions: The therapeutic significance of macrophages in the field of NSCLC is gaining increasing attention and recognition, highlighting their potential as key players in the development of novel treatment strategies. Future research will focus on understanding TAM molecular mechanisms, interactions with immune cells, and exploring novel therapies, with the aim of improving NSCLC treatment outcomes.
Subject(s)
Bibliometrics , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Animals , Humans , Biomedical Research/trends , Carcinoma, Non-Small-Cell Lung/immunology , Carcinoma, Non-Small-Cell Lung/therapy , Carcinoma, Non-Small-Cell Lung/pathology , Immunotherapy/methods , Lung Neoplasms/therapy , Lung Neoplasms/immunology , Lung Neoplasms/pathology , Macrophages/immunology , Tumor Microenvironment/immunologyABSTRACT
Semiquinone (SQ) radicals play a critical role in the long-lasting UV-blocking application of lignin, while their origin and stable structure are unclear. Here, the organosolv lignin extracted from poplar (OL-P) is self-assembled into normal micelles (LNM) with more phenolic hydroxyl groups on the surface, and reverse micelles (LRM) with more methoxyl groups on the surface. After 12 h UV irradiation, the SQ radical contents in LNM and LRM increase 33% and 78% respectively. The performance of LNM based sunscreen keeps upswinging due to radical stabilization of phenolic hydroxyl groups. LRM based sunscreen experiences a gradual decrease after reaching maximum UV absorbance due to the quick generation and over oxidation of SQ radicals. Density functional theory (DFT) simulations reveal that methoxyl groups in OL-P has bigger bond length and smaller bond dissociation enthalpy than phenolic hydroxyl groups, and are easy to form SQ radicals. The Gibbs free energy (ΔG) needed for SQ-quinone transformation is above 26.10 kcal mol.-1 , while that for SQ-hydroquinone transformation is below -66.78 kcal mol.-1 . Hydroquinone is the stable structure of SQ radicals. This work discloses the origin and stable structure of SQ radicals in lignin under UV irradiation, and provides an important guidance for its long-lasting UV-blocking application.
ABSTRACT
BACKGROUND: Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are closely related to the prognosis of patients with non-small cell lung cancer, but their effect on extensive-stage small cell lung cancer (ES-SCLC) remains uncertain. METHODS: This retrospective study was conducted in ES-SCLC patients treated with first-line atezolizumab or durvalumab and platinum-etoposide. Clinical data from three hospitals were analyzed. Significant risk factors for survival were identified using descriptive statistics and Cox regression. Homogeneity was assessed using t-tests or nonparametric tests. Kaplan-Meier analysis revealed an association between high NLR level and median PFS and OS. RESULTS: A total of 300 ES-SCLC patients were included in the study. Cox regression analysis revealed that an elevated NLR level after the second treatment cycle (defined as NLRT2) was an independent prognostic factor for survival. Stratifying patients based on median NLRT2 showed significant differences in both PFS (HR: 1.863, 95% CI: 1.62-2.12, p < 0.001) and OS (HR: 2.581, 95% CI: 2.19-3.04, p < 0.001) between NLR ≥ 1.75 and NLR < 1.75 groups. mPFS and mOS were 8.2 versus 6.1 months and 13.7 versus 9.5 months, respectively. NLR was also associated with treatment efficacy and occurrence of irAEs. Further stratification based on NLR and irAEs showed that in the NLR < 1.75 group, patients with irAEs had prolonged mPFS and mOS. In the NLR ≥ 1.75 group, only mPFS showed a significant difference between patients with and without irAEs. CONCLUSION: NLRT2 and irAEs can predict the prognosis of ES-SCLC patients with first-line ES-SCLC receiving PD-L1 inhibitors combined with chemotherapy.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Small Cell Lung Carcinoma , Humans , Carcinoma, Non-Small-Cell Lung/drug therapy , Neutrophils , Prognosis , Retrospective Studies , LymphocytesABSTRACT
In the research presented herein, low-valent-tungsten-catalyzed hydroboration of esters and nitriles was investigated. Aromatic and aliphatic substrates were smoothly reduced to corresponding alcohol derivatives and N,N-diborylamines in the presence of W(CO)4(NCMe)2. Valuable derivatives were conveniently accessed by introducing a further functionalization process to crude hydroboration mixtures in one pot.