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Although nanoscale surface roughness has been theoretically demonstrated to be a crucial factor in the interaction of colloids and surfaces, little experimental research has investigated the influence of roughness on colloid or silver nanoparticle (AgNP) retention and release in porous media. This study experimentally examined AgNP retention and release using two sands with very different surface roughness properties over a range of solution pH and/or ionic strength (IS). AgNP transport was greatly enhanced on the relatively smooth sand in comparison to the rougher sand, at higher pH, and lower IS and fitted model parameters showed systematic changes with these physicochemical factors. Complete release of the retained AgNPs was observed from the relatively smooth sand when the solution IS was decreased from 40 mM NaCl to deionized (DI) water and then the solution pH was increased from 6.5 to 10. Conversely, less than 40% of the retained AgNPs was released in similar processes from the rougher sand. These observations were explained by differences in the surface roughness of the two sands which altered the energy barrier height and the depth of the primary minimum with solution chemistry. Limited numbers of AgNPs apparently interacted in reversible, shallow primary minima on the smoother sand, which is consistent with the predicted influence of a small roughness fraction (e.g., pillar) on interaction energies. Conversely, larger numbers of AgNPs interacted in deeper primary minima on the rougher sand, which is consistent with the predicted influence at concave locations. These findings highlight the importance of surface roughness and indicate that variations in sand surface roughness can greatly change the sensitivity of nanoparticle transport to physicochemical factors such as IS and pH due to the alteration of interaction energy and thus can strongly influence nanoparticle mobility in the environment.

Background and purposeLike chili peppers, gingers produce pungent stimuli by a group of vanilloid compounds that activate the nociceptive transient receptor potential vanilloid 1 (TRPV1) ion channel. How these compounds interact with TRPV1 remains unclear.Experimental approachWe used computational structural modelling, functional tests (electrophysiology and calcium imaging), and mutagenesis to investigate the structural mechanisms underlying ligand-channel interactions.Key resultsThe potency of three principal pungent compounds from ginger -shogaol, gingerol, and zingerone-depends on the same two residues in the TRPV1 channel that form a hydrogen bond with the chili pepper pungent compound, capsaicin. Computational modelling revealed binding poses of these ginger compounds similar to those of capsaicin, including a "head-down tail-up" orientation, two specific hydrogen bonds, and important contributions of van der Waals interactions by the aliphatic tail. Our study also identified a novel horizontal binding pose of zingerone that allows it to directly interact with the channel pore when bound inside the ligand-binding pocket. These observations offer a molecular level explanation for how unique structures in the ginger compounds affect their channel activation potency.Conclusions and implicationsMechanistic insights into the interactions of ginger compounds and the TRPV1 cation channel should help guide drug discovery efforts to modulate nociception.

Piperine, the principle pungent compound in black peppers, is known to activate the capsaicin receptor TRPV1 ion channel. How piperine interacts with the channel protein, however, remains unclear. Here we show that piperine binds to the same ligand-binding pocket as capsaicin but in different poses. There was no detectable detrimental effect when T551 and E571, two major sites known to form hydrogen bond with capsaicin, were mutated to a hydrophobic amino acid. Computational structural modeling suggested that piperine makes interactions with multiple amino acids within the ligand binding pocket, including T671 on the pore-forming S6 segment. Mutations of this residue could substantially reduce or even eliminate piperine-induced activation, confirming that T671 is an important site. Our results suggest that the bound piperine may directly interact with the pore-forming S6 segment to induce channel opening. These findings help to explain why piperine is a weak agonist, and may guide future efforts to develop novel pharmaceutical reagents targeting TRPV1.

As an emerging class of nanoporous materials, metal–organic frameworks (MOFs) have the advantages of designability and structural and functional tunability, compared with traditional porous materials, which are widely used in various fields. The structural adjustability of MOFs provides the possibility of infinite material generation and a huge material space. At present, tens of thousands of MOFs have been synthesized and the number continues to grow at an alarming rate, which makes it difficult to explore the application prospects of all materials only by traditional experimental methods. Therefore, more efficient alternative methods are urgently needed to identify and screen MOFs. As a powerful data analysis tool, machine learning (ML) has shown great potential in the materials field, which can intuitively and quickly analyze the structure–property relationship and guide the rational design and preparation of reticular materials such as MOFs. This review systematically presents the complete workflow and cutting-edge developments in ML applications in the field of MOF research covering data preparation, algorithm selection, model evaluation, model optimization and application status. Further, rational design methods and future challenges are discussed. This review aims to provide the new paradigm of the combination of ML and MOFs and promote ML applied in MOF research efficiently. [ABSTRACT FROM AUTHOR]

With the continuous growth of the global submarine cable laying length, the frequency of faults and the caused economic losses are increasing year by year. Rapid identification of submarine cable faults can reduce economic losses. For several typical submarine cable faults, this paper proposes a recognition method based on FCN-GRU-SVM. First, pre-process the original signal, then import the data into FCN-GRU to extract the signal features, and finally use SVM to identify the fault types. The experimental verification using the data set obtained by finite element simulation shows that the proposed method is superior to the comparison model and other time-frequency processing methods in accuracy and robustness.

The coastal area of Jiangsu Province was selected as the research area, which has a unique muddy coastal zone and diverse beach wetland ecosystem with good development advantages and potential. We construct the evaluation system with five indexes such as wetland, forest land, key functional areas, rivers entering the sea and soil. By using space technologies of GIS, the evaluation unit was composed of districts, counties and grids of Nantong, Yancheng and Lianyungang, and the ecological carrying capacity was calculated through evaluation of single index and comprehensive evaluation of multiple indexes. This paper analyzed the spatial pattern heterogeneity of ecological carrying suitability in coastal areas, revealed the influencing factors causing the difference of spatial bearing state. The results showed that the ecological carrying capacity of the study area in terms of "suitable", "less suitable", "general suitable", "controlled" and "unsuitable" is 16.59%, 11.22%, 38.50%, 17.15% and 16.54% respectively. There is significant heterogeneity in the spatial pattern of the bearing capacity, and the distribution showed characteristics of " low in the middle, high in the north and south". The bearing capacity of Nantong in the south is relatively higher than that of Lianyun in the north, mainly for "suitable" and "more suitable" distribution areas. The ecological carrying capacity of the central Yancheng area is significantly lower than that of other areas, mainly for the "unsuitable" and "controlled" distribution areas. [ABSTRACT FROM AUTHOR]

Based on wrinkling model,a theoretical model for thermal barrier coating system was established. Using the temperature parameter method,the paper constructed the residual stress field of coating system,built the discrete format of finite element for lower coating shakedown analysis,and analyzed the effects of wrinkling degree and oxide layer thickness on coating system shakedown limit. Aiming at the geometric characteristics of wrinkling model,this paper translated it into a cylindrical model with three layers,provided analytic expressions for the shakedown limits,and then set up the simplified analytic model of thermal barrier coating. Compared with the numerical results,when C / L is less than 1 or C is far less than L,namely when wrinkle degree is not very drastic,the simplified model is close to the numerical results and it can be as an approximate calculation method for the shakedown limit of thermal barrier coating.

Based on the concept of contact counterforce between gear pair,the paper studied the meshing efficiency of involute spur gear mechanism,analyzed the effect factors of friction coefficient between contact tooth surfaces. Referring to the existent research models of friction coefficient,the paper discussed the meshing characteristics of spur gear and helical gear’s transmission,and derived the mathematic expressions of instantaneous meshing efficiency and average meshing efficiency for gear transmission of spur gear and helical gear. And then under the situation of different transmission ratios,pressure angles and friction coefficients,the paper analyzed the meshing efficiency of gear mechanism. The results show that friction coefficients are in inverse proportion to gear meshing efficiency,biggish pressure angles and transmission ratios contribute to improve gear meshing efficiency,and the meshing efficiency of increasing gear is higher than reducing gear.

Background: Pleural mesothelioma (PM) is a relatively rare malignancy with limited treatment options and dismal prognosis. We have previously found elevated FGF18 expression in PM tissue specimens compared with normal mesothelium. The objective of the current study was to further explore the role of FGF18 in PM and evaluate its suitability as a circulating biomarker. Methods: FGF18 mRNA expression was analyzed by real‐time PCR in cell lines and in silico in datasets from the Cancer Genome Atlas (TCGA). Cell lines overexpressing FGF18 were generated by retroviral transduction and cell behavior was investigated by clonogenic growth and transwell assays. Plasma was collected from 40 PM patients, six patients with pleural fibrosis, and 40 healthy controls. Circulating FGF18 was measured by ELISA and correlated to clinicopathological parameters. Results: FGF18 showed high mRNA expression in PM and PM‐derived cell lines. PM patients with high FGF18 mRNA expression showed a trend toward longer overall survival (OS) in the TCGA dataset. In PM cells with low endogenous FGF18 expression, forced overexpression of FGF18 resulted in reduced growth but increased migration. Surprisingly, despite the high FGF18 mRNA levels observed in PM, circulating FGF18 protein was significantly lower in PM patients and patients with pleural fibrosis than in healthy controls. No significant association of circulating FGF18 with OS or other disease parameters of PM patients was observed. Conclusions: FGF18 is not a prognostic biomarker in PM. Its role in PM tumor biology and the clinical significance of decreased plasma FGF18 in PM patients warrant further investigation. [ABSTRACT FROM AUTHOR]