•A pore-blocking SMA (PB-SMA) model was developed for bioparticles adsorption.•The model considers pore-blocking behavior of large-size bioparticles on adsorbent.•A parameter reflecting inaccessible ...ligand due to pore blocking was introduced.•The σ from PB-SMA was dozens of times smaller than that from conventional SMA model.•The model is applicable to bioparticles adsorption on different types of adsorbents.
The steric mass-action (SMA) model has been widely reported to describe the adsorption of proteins in different types of chromatographic adsorbents. Here in the present work, a pore-blocking steric mass-action model (PB-SMA) was developed for the adsorption of large-size bioparticles, which usually exhibit the unique pore-blocking characteristic on the adsorbent and thus lead to a fraction of ligands in the deep channels physically inaccessible to bioparticles adsorption, instead of being shielded due to steric hindrance by adsorbed bioparticles. This unique phenomenon was taken into account by introducing an additional parameter, Lin, which is defined as the inaccessible ligand densities in the physically blocked pore area, into the PB-SMA model. This fraction of ligand densities (Lin) will be deducted from the total ligand (Lt) for model development, thus the steric factor (σ) in the proposed PB-SMA will reflect the steric shielding effect on binding sites by adsorbed bioparticles more accurately than the conventional SMA model, which assumes that all ligands on the adsorbent have the same accessibility to the bioparticles. Based on a series of model assumptions, a PB-SMA model was firstly developed for inactivated foot-and-mouth disease virus (iFMDV) adsorption on immobilized metal affinity chromatography (IMAC) adsorbents. Model parameters for static adsorption including equilibrium constant (K), characteristic number of binding sites (n), and steric factor (σ) were determined. Compared with those derived from the conventional SMA model, the σ values derived from the PB-SMA model were dozens of times smaller and much closer to the theoretical maximum number of ligands shielded by a single adsorbed iFMDV, indicating the modified model was more accurate for bioparticles adsorption. The applicability of the PB-SMA model was further validated by the adsorption of hepatitis B surface antigen virus-like particles (HBsAg VLPs) on an ion exchange adsorbent with reasonably improved accuracy. Thus, it is considered that the PB-SMA model would be more accurate in describing the adsorption of bioparticles on different types of chromatographic adsorbents.
Recognition of complex dynamic texture is a difficult task and captures the attention of the computer vision community for several decades. Essentially the dynamic texture recognition is a ...multi-class classification problem that has become a real challenge for computer vision and machine learning techniques. Due to the reason that the dynamic textures lie in non-Euclidean manifold, existing classifier such as extreme learning machine cannot effectively deal with this problem. In this paper, we propose a new approach to tackle the dynamic texture recognition problem. First, we utilize the affinity propagation clustering technology to design a codebook, and then construct a soft coding feature to represent the whole dynamic texture sequence. This new coding strategy preserves spatial and temporal characteristics of dynamic texture. Finally, by evaluating the proposed approach on the DynTex dataset, we show the effectiveness of the proposed strategy.
Excessive formation of neutrophil extracellular traps (NETs) may lead to myositis-related interstitial lung disease (ILD). There is evidence that NETs can directly injure vascular endothelial cells ...and play a pathogenic role in the inflammatory exudation of ILD. However, the specific mechanism is unclear. This study aimed to investigate the specific mechanism underlying NET-induced injury to human pulmonary microvascular endothelial cells (HPMECs). HPMECs were stimulated with NETs (200 ng/ml) in vitro. Cell death was detected by propidium iodide staining. The morphological changes of the cells were observed by transmission electron microscopy (TEM). Pyroptosis markers were detected by western blot, immunofluorescence and quantitative real-time PCR, and the related inflammatory factor IL-1β was verified by ELISA. Compared with the control group, HPMECs mortality increased after NET stimulation, and the number of pyroptosis vacuoles in HPMECs was further observed by TEM. The pulmonary microvascular endothelial cells (PMECs) of the experimental autoimmune myositis (EAM) mouse model also showed a trend of pyroptosis in vivo. Cell experiment further confirmed the significantly high expression of the NLRP3 inflammasome and pyroptosis-related markers, including GSDMD and inflammatory factor IL-1β. Pretreated with the NLRP3 inhibitor MCC950, the activation of NLRP3 inflammasome and pyroptosis of HPMECs were effectively inhibited. Our study confirmed that NETs promote pulmonary microvascular endothelial pyroptosis by activating the NLRP3 inflammasome, suggesting that NETs-induced pyroptosis of PMECs may be a potential pathogenic mechanism of inflammatory exudation in ILD.
•Benzisothiazole alkali-resistant disperse dyes containing hydrolysis groups were synthesized.•Different substituents were introduced into the adjacent position of cyano group in the dyes.•The ...relationship between adjacent substituents and alkali resistance was investigated.•The hydrolysis mechanism of disperse dyes in alkaline dyeing was revealed by DFT calculation.
Dyes containing cyano group have the advantages of bright colours and high molar absorption. However, most cyano-containing disperse dyes are not used for alkaline dyeing as they are easily hydrolysed under alkali conditions. Herein, cyano-containing disperse dyes for alkaline dyeing were designed by introducing non-hydrolysable phenylethyl and potentially alkali-hydrolysable ethyl benzoate in adjacent positions to the cyano group, and the effect of the adjacent groups on the alkali resistance of cyano-containing dyes was investigated. Polyester fabric (PET) was dyed under different acidic or alkali conditions by the disperse dyes, then the hydrolysis energy barrier of cyano on the dye and the binding energy of dye-dye and dye-PET under the dyeing conditions were calculated via Density Functional Theory (DFT). The results showed that the cyano-containing disperse dyes with an adjacent benzene ring structure had good alkali resistance in a 5 g/L NaOH dye bath. DFT simulations confirmed that the adjacent phenylethyl did not have a significant effect on the hydrolytic energy barrier of the cyano group, while the adjacent ethyl benzoate reduced the hydrolytic energy barrier of the cyano group. The introduction of an adjacent benzene ring reduced the dye-dye binding energy, contributing to the increasement of dyeing rate at the beginning of the dyeing process. The designed cyano-containing dyes with adjacent benzene rings achieved a colour fastness level of 4–5 or above in various acid and alkali conditions.
The Tcra repertoire is generated by multiple rounds of Vα-Jα rearrangement. However, Tcrd recombination precedes Tcra recombination within the complex Tcra-Tcrd locus. Here, by ablating Tcrd ...recombination, we report that Tcrd rearrangement broadens primary Vα use to diversify the Tcra repertoire in mice. We reveal that use of Trav15-dv6 family V gene segments in Tcrd recombination imparts diversity in the Tcra repertoire by instigating use of central and distal Vα segments. Moreover, disruption of the regions containing these genes and their cis-regulatory elements identifies the Trav15-dv6 family as being responsible for driving central and distal Vα recombinations beyond their roles as substrates for Tcrd recombination. Our study demonstrates an indispensable role for Tcrd recombination in general, and the Trav15-dv6 family in particular, in the generation of a combinatorially diverse Tcra repertoire.
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•A bamboo fiber/graphene oxide (M−CBF−rGO) aerogel with a sponge-like porous structure was fabricated.•The M−CBF−rGO shows excellent superelasticity and mechanical durability (7,000 ...cycles).•The derived sensor exhibits superior operating range (0–300 kPa) and strain sensitivity (892.9).•The sensor can be capable of detecting human physiological signals and monitoring human activity.
Superelastic, breathable, and flexible piezoresistive sensors with excellent sensing performance are drawing tremendous attention in wearable electronics and sleeping furnishings. However, simultaneous realization of their high performance is still a huge challenge. In this study, inspired by the pore structure of natural sponges, a high-performance sponge-like bamboo fiber/graphene oxide aerogel piezoresistive sensor (M−CBF−rGO) was prepared utilizing bamboo fibers (BFs) and graphene oxide (GO) as raw materials through freeze casting and carbonization. Benefiting from the unique porous structure with effective absorbing/releasing energy, the M−CBF−rGO aerogel sensor exhibits excellent superelasticity (not being destroyed under 90 % deformation), mechanical durability (7,000 cycles), and good breathability. Moreover, the M−CBF−rGO sensor demonstrates ultra-high strain sensitivity (892.9), a wide detection range (0–300 kPa), and a fast recovery time (20 ms). Taking advantage of these benefits, the M−CBF−rGO sensor can not only be applied to detect human signals ranging from finger motion to swallowing recognition, but also integrated into the cushioning materials of upholstered furniture to generate a sensing array for monitoring and recogniting human activity including sitting postures and sleeping positions in real-time. This sensor demonstrates the potential application prospects in the fields of human health diagnosis, smart wearable products, and intelligent upholstered furniture.
•Interaction mechanism of saponins and pancreatic lipase was investigated in vitro.•The effects of saponins on the reaction kinetics of pancreatic lipase were examined.•The effects of saponins on the ...thermodynamics of pancreatic lipase were elucidated.•The effects of saponins on the conformation of pancreatic lipase were evaluated.•Morphology and solubility of PL in the presence of saponins was studied.
The molecular interactions between pancreatic lipase (PL) and five triterpenoid saponins compounds, including tea saponin, oleanolic acid, betulin, ginsenoside Ro, and ginsenoside Rd, were investigated in vitro through comprehensive evaluation of PL activity, conformation, reaction kinetics, thermodynamics, aggregation morphology and solubility. All tested saponins inhibited PL activity, and their inhibitory ratios showed structure- and concentration-dependence. Tea saponin possessed competitive inhibition against PL activity, and affected PL secondary structure, while other four saponins non-competitively inhibited PL activity and affected PL tertiary structure. However, all tested saponins could statically quench PL fluorescence. Soluble PL-saponins complexes were characterized by AMF, DLS and Bio-Rad method, and PL showed self-assembly phenomenon in the presence of saponins, which possessed a close contribution to the inhibitory ratios. DSC measurement revealed that five tested saponins compounds had variant influence on PL enzyme thermal stability parameters (Tm and ΔH).
A series of adamantane-based ionic liquids (ADM-ILs) with MF n − anions were synthesized as cocatalysts for the alkylation of isobutane and butene. By systematically tuning the structures of the ...cation and anion and their combination, we obtained the optimized ionic liquid, ADM-C12-SbF6, which exhibited significant enhancements in the C8 selectivities especially to trimethylpentanes (TMPs), the research octane number (RON) of the alkylate products, and the lifetime of sulfuric acid. The selectivity to TMPs was improved from 81.9% to 84.5%, and the alkylate RON was improved from 96.6 to 98.6 upon the addition of the ADM-ILs. In addition, the lifetimes of the ADM-IL/H2SO4 systems were increased to twice that of H2SO4 alone. Based on experimental measurements and DFT calculations, all of these enhancements were attributed to the multifunctions cooperatively integrated into the task-specific ADM-ILs, such as surfactant action, improving the interfacial properties of the acid/hydrocarbon biphases; buffer action, stabilizing the acidity changes during the reaction process; and hydride donor action, increasing the H– transfer rate, which promoted the production of TMPs. This study is beneficial for improving the isobutane alkylation process catalyzed by concentrated sulfuric acid.
Graphene oxide/nylon 11 composites were prepared by in situ melt polycondensation. These composites displayed better mechanical properties including stiffness and toughness than the pure nylon 11 ...matrix. The enhanced toughness was ascribed to the change of crystal form of nylon 11, namely the triclinic α crystal form to the pseudo-hexagonal δ′ crystal form transition trend with the incorporation of GO. Scanning electron microscopy and transmission electron microscopy images showed that GO bundles and stacks with an average thickness of 20nm are homogeneously dispersed over the nylon 11 matrix with almost no large agglomerates.
