The role of conformational dynamics in the activity of polymer-conjugated CalB in organic solvents.

Perennial interest in enzyme catalysis has been expanding its applicability from aqueous phases where enzymes are naturally evolved to organic solvents in which the majority of industrial chemical syntheses are carried out. Although conjugating an enzyme with a soluble polymer has been attempted to enhance enzyme activity in organic solvents, the underlying mechanism remains poorly understood in terms of the conformational dynamics and enzyme activity. Herein, we combine LF-NMR measurements and MD simulations to investigate the effects of polymer grafting on the conformational dynamics of CalB in organic solvents and the consequential impacts on the catalytic kinetics, using the lipase-catalyzed transesterification reaction as a model system. LF-NMR measurements confirm that conjugation with a soluble polymer improves the enzyme flexibility in organic solvents, leading to an increase in the catalytic efficiency of up to two orders of magnitude. MD simulations suggest that the conjugated enzyme samples a larger conformational space, compared to its native counterpart, validating the hypothesis that polymer motion enhances enzyme dynamics. These experimental and simulation results provide new insights for enhancing enzyme conformational dynamics and thereby catalytic kinetics in organic solvents.

[Mechanism of Qingwei Powder in treatment of periodontitis based on UPLC-Q-TOF-MS, GC-MS, network pharmacology and molecular docking].

The present study explored the mechanism of Qingwei Powder(QP) in the treatment of periodontitis based on chromatography-mass spectrometry and network pharmacology-molecular docking techniques. UPLC-Q-TOF-MS and GC-MS were used to identify the chemical constituents of QP. The active components and targets were screened out through the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP), and their targets were predicted using SwissTargetPrediction. Targets related to periodontitis were obtained from GeneCards, OMIM, and DisGeNET. Venn diagram was constructed using Venny 2.1 to obtain the intersection targets. Cytoscape 3.7.2 was used to construct the "chemical component-target-disease" network. The targets were analyzed for Gene Ontology(GO) function and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment by clusterProfiler R, and the "chemical component-target-pathway" network was constructed. The binding activity of the active components to the target proteins was verified by molecular docking. A total of 189 chemical components were obtained by UPLC-Q-TOF-MS and GC-MS, including 39 active components with 180 potential targets related to periodontitis. Target enrichment analysis of the active components yielded 92 KEGG pathways. Twenty KEGG pathways, 34 active components, and 99 targets were involved in the "chemical component-target-pathway" network. Molecular docking verified a good binding ability of the key targets to the key compounds. This study preliminarily indicates that QP is effective in treating periodontitis through multiple components, multiple targets, and multiple pathways, which reflects the complex system of Chinese medicine. This study provides the theoretical foundation for the subsequent research on the material basis and key quality attributes of QP.

In Situ Identification and Spatial Mapping of Microplastic Standards in Paramecia by Secondary-Ion Mass Spectrometry Imaging.

Microplastics (MPs) are universally present in the ecosystem and pose great threats to the environment and living organisms. Research studies have shown that small MPs (<50 µm in diameter) are especially toxic and account for more than half of all MPs collected in the Atlantic Ocean. Nevertheless, current methods for the detection and analysis of MPs are incapable of achieving rapid and in situ analysis of small MPs in the biota to ultimately enable the study of their biological effects. In this work, we report a method that allows rapid in situ identification and spatial mapping of small MPs directly from paramecia with high accuracy by acquiring chemical composition information using secondary-ion mass spectrometry (SIMS) imaging. Specifically, six types of common MPs (polymethyl methacrylate, polyvinyl chloride, polypropylene, polyethylene terephthalate, polyglycidyl methacrylate, and polyamide 6) with a diameter of 1-50 µm were simultaneously imaged with high chemical specificity at a spatial resolution of 700 nm. In situ spatial mapping of a group of MPs ingested by paramecia was performed using SIMS fragments specific to the plastic composition with no sample pretreatment, revealing the aggregation of MPs in paramecia after ingestion. Compared with existing methods, one additional advantage of the developed method is that the MPs and the organism can be analyzed in the same experimental workflow to record their fingerprint spectra, acquiring biochemical information to evaluate MP fate, toxicity, and the MP-biota interaction.

Analysis of the influencing factors of PAEs volatilization from typical plastic products.

The primary emphasis of this research was to investigate the foundations of phthalate (PAEs) pollutant source researches and then firstly confirmed the concept of the coefficient of volatile strength, namely phthalate total content in per unit mass and unit surface area of pollutant sources. Through surveying and evaluating the coefficient of volatile strength of PAEs from typical plastic products, this research carried out reasonable classification of PAEs pollutant sources into three categories and then investigated the relationship amongst the coefficient of volatile strength as well as other environmental factors and the concentration level of total PAEs in indoor air measured in environment chambers. Research obtained phthalate concentration results under different temperature, humidity, the coefficient of volatile strength and the closed time through the chamber experiment. In addition, this study further explored the correlation and ratio of influencing factors that affect the concentration level of total PAEs in environment chambers, including environmental factors, the coefficient of volatile strengths of PAEs and contents of total PAEs in plastic products. The research created an improved database system of phthalate the coefficient of volatile strengths of each type of plastic goods, and tentatively revealed that the volatile patterns of PAEs from different typical plastic goods, finally confirmed that the coefficient of volatile strengths of PAEs is a major factor that affects the indoor air total PAEs concentration, which laid a solid foundation for further establishing the volatile equation of PAEs from plastic products.

Osteocytes Enhance Osteogenesis by Autophagy-Mediated FGF23 Secretion Under Mechanical Tension.

Mechanical stimuli control cell behaviors that are crucial for bone tissue repair. Osteocytes sense extracellular mechanical stimuli then convert them into biochemical signals to harmonize bone remodeling. However, the mechanisms underlying this process remain unclear. Autophagy, which is an evolutionarily preserved process, that occurs at a basal level when stimulated by multiple environmental stresses. We postulated that mechanical stimulation upregulates osteocyte autophagy via AMPK-associated signaling, driving osteocyte-mediated osteogenesis. Using a murine model of orthodontic tooth movement, we show that osteocyte autophagy is triggered by mechanical tension, increasing the quantity of LC3B-positive osteocytes by 4-fold in the tension side. Both in vitro mechanical tension as well as the chemical autophagy agonist enhanced osteocyte Fibroblast growth factor 23 (FGF23) secretion, which is an osteogenenic related cytokine, by 2-and 3-fold, respectively. Conditioned media collected from tensioned osteocytes enhanced osteoblast viability. These results indicate that mechanical tension drives autophagy-mediated FGF23 secretion from osteocytes and promotes osteogenesis. Our findings highlight a potential strategy for accelerating osteogenesis in orthodontic clinical settings.

Randomized Phase 2 Studies of Checkpoint Inhibitors Alone or in Combination With Pegilodecakin in Patients With Metastatic NSCLC (CYPRESS 1 and CYPRESS 2).

INTRODUCTION: Checkpoint inhibitors (CPIs) have been approved to treat metastatic NSCLC. Pegilodecakin + CPI suggested promising efficacy in phase 1 IVY, providing rationale for randomized phase 2 trials CYPRESS 1 and CYPRESS 2. METHODS: CYPRESS 1 (N = 101) and CYPRESS 2 (N = 52) included Eastern Cooperative Oncology Group performance status of 0 to 1 and first-line/second-line metastatic NSCLC, respectively, without known EGFR/ALK mutations. Patients were randomized 1:1; control arms received pembrolizumab (CYPRESS 1) or nivolumab (CYPRESS 2); experimental arms received pegilodecakin + CPI. Patients had programmed death-ligand 1 tumor proportion score of greater than or equal to 50% (CYPRESS 1) or 0% to 49% (CYPRESS 2). Primary end point was objective response rate (ORR) per investigator. Secondary end points included progression-free survival (PFS), overall survival (OS), and safety. Exploratory end points included immune activation biomarkers. RESULTS: Median follow-up for CYPRESS 1 and CYPRESS 2 was 10.0 and 11.6 months, respectively. Results for pegilodecakin + pembrolizumab versus pembrolizumab were as follows: ORR per investigator 47% versus 44% (OR = 1.1, 95% confidence interval [CI]: 0.5-2.5); median PFS 6.3 versus 6.1 months (hazard ratio [HR] = 0.937, 95% CI: 0.54-1.625); and median OS 16.3 months versus not reached (HR = 1.507, 95% CI: 0.708-3.209). Results per blinded independent central review were consistent. Treatment discontinuation rate owing to adverse events (AEs) doubled in the experimental arm (32% versus 15%). AEs with grade greater than or equal to 3 treatment-related AEs (62% versus 19%) included anemia (20% versus 0%) and thrombocytopenia (12% versus 2%). Results for pegilodecakin + nivolumab versus nivolumab were as follows: ORR per investigator 15% versus 12% (OR = 1.2, 95% CI: 0.3-5.9); median PFS 1.9 versus 1.9 months (HR = 1.006, 95% CI: 0.519-1.951); and median OS 6.7 versus 10.7 months (HR = 1.871, 95% CI: 0.772-4.532). AEs with grade greater than or equal to 3 treatment-related AEs (70.4% versus 16.7%) included anemia (40.7% versus 0%), fatigue (18% versus 0%), and thrombocytopenia (14.8% versus 0%). Biomarker data suggested activation of immunostimulatory signals of interleukin-10R pathway in pegilodecakin-containing arms. CONCLUSIONS: Despite evidence of biological effect in peripheral blood, adding pegilodecakin to CPI did not improve ORR, PFS, or OS, in first-line/second-line NSCLC. Pegilodecakin + CPI has been found to have overall higher toxicity compared with CPI alone, leading to doubling of treatment discontinuation rate owing to AEs.

Percutaneous sclerotherapy with polidocanol under the guidance of ultrasound for venous malformations in children - A retrospective cohort study from a single tertiary medical center.

This study reports our experience, the therapeutic outcomes and complications of percutaneous sclerotherapy (PS) with polidocanol to treat venous malformations (VMs) in children.A retrospective analysis was conducted of pediatric patients with VMs who underwent PS using polidocanol under continuous ultrasound (US) guidance between January 2015 and January 2018 at our department. Medical records were reviewed to record demographic information, lesion characteristics, treatment sessions, therapeutic outcomes and complications. χ analysis was employed to evaluate the effects of these characteristics on outcomes.Hundred treatment sessions were performed for lesions in 47 patients. The mean age of the patients was 4.1 ±â€Š3.6 years (mean ±â€ŠSD). The female to male ratio was almost 2:1 (female 32, male 15). The location of the VMs included the head and neck in 16 cases (34.0%), upper extremity in 11 cases (23.4%), lower extremity in 10 cases (21.3%), and trunk and perineum in 10 cases (21.3%). The majority of the lesions were focal in 36 cases (76.6%), while 11 (23.4%) were diffuse. Seventeen patients (36.2%) underwent single PS session, 14 patients (29.8%) underwent 2 sessions, 10 patients (21.3%) underwent 3 sessions and 6 patients (12.7%) underwent ≧4 sessions. The mean PS session per patient was 2.1 ±â€Š1.1. The mean follow-up duration was 11.4 ±â€Š7.6 months. After the last PS session, 8 patients (17.0%) had excellent outcomes, 27 (57.4%) had good outcomes, 10 (21.3%) had fair outcomes, and 2 (4.3%) had poor outcomes. Focal lesions were more likely to have good or excellent outcomes than diffuse lesions (χ = 4.522, P = .033). No other lesion characteristic significantly affected the outcomes (good or excellent outcomes), including lesion location (χ = 2.011, P = .570) or lesion size (χ = 1.045, P = .307). After the PS procedure, temporary local swelling occurred in 81 sessions (81.0%), local pain occurred in 15 sessions (15.0%), fever occurred in 27 (27.0%) sessions, and transient local numbness occurred in four sessions (4.0%).PS with polidocanol under the guidance of US appears to be safe and effective for the treatment of VMs in children, especially for focal lesions.

Drug-free and non-crosslinked chitosan scaffolds with efficient antibacterial activity against both Gram-negative and Gram-positive bacteria.

Treatment of oral pathogens is important for both oral and systemic health. The antimicrobial activity of chitosan (CS)-based scaffolds either loading antibiotics or compositing with other agents are well documented. However, the intrinsic antibacterial activity of CS scaffolds alone has never been reported. Herein, we fabricated the non-crosslinked CS scaffold and investigated its antibacterial activity against typical oral pathogens, Gram-negative Porphyromonas gingivalis and Gram-positive Streptococcus mutans. We found both pathogens were completely killed by 1 mg CS scaffolds at 6 h, due largely to the CS-induced time-dependent bacteria clustering. Interestingly, ß-glycerophosphate crosslinked scaffolds showed no antibacterial activity. In conclusion, the bactericidal activity of CS scaffolds alone is reported for the first time. Together with the biodegradability, physical stability, biocompatibility and great antibacterial activity, the non-crosslinked CS scaffolds may have great potentials not only in treating oral diseases but also in wound healing and tissue engineering.

An evaporation induced self-assembly approach to prepare polymorphic carbon dot fluorescent nanoprobes for protein labelling.

Herein, we report a novel route to prepare polymorphic carbon dot fluorescent probes via the evaporation-induced self-assembly of glutaraldehyde and carbon dots, which first usually form carbon nanoclusters which then could self-assemble to form carbon nanocrystals, nanospheres or nanofibers in different ionic strength solutions at room temperature. The aldehyde functionalized polymorphic C-dot fluorescent probe can easily covalently bond with amino groups on proteins.

[Photoelastic analysis of mandibular edentulous alveolar bone with denture adhesives].

PURPOSE: To compare the stress distribution of supporting tissues in Atwood level 3 alveolar bones under the mandibular complete dentures with and without denture adhesives. METHODS: Photoelastic models of epoxy were fabricated according to the standard Atwood level 3 edentulous model. 1.5 kg force was vertically applied on the bite force loading device. After stress frozen, photoelastic model slices in posterior teeth area were observed and analyzed. RESULTS: When using denture adhesives, stresses distributed more adequately in the buccal and lingual side and the force of alveolar crest increased remarkably. CONCLUSIONS: To those with Atwood level 3 alveolar ridge and complete denture, denture adhesives can not only increase stability but also prevent local pressure under uneven stress distribution.