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Thrombosis associated with implants can severely impact therapeutic outcomes and lead to increased morbidity and mortality. Thus, developing blood-contacting materials with superior anticoagulant properties is essential to prevent and mitigate device-related thrombosis. Herein, we propose a novel single-molecule multi-functional strategy for creating blood-compatible surfaces. The synthesized azide-modified Cu-DOTA-(Lys)3molecule, which possesses both NO release and fibrinolysis functions, was immobilized on material surfaces via click chemistry. Due to the specificity, rapidity, and completeness of click chemistry, the firmly grafted Cu-DOTA-(Lys)3endows the modified material with excellent antithrombotic properties of vascular endothelium and thrombolytic properties of fibrinolytic system. This surface effectively prevented thrombus formation in both in vitroand in vivoexperiments, owing to the synergistic effect of anticoagulation and thrombolysis. Moreover, the modified material maintained its functional efficacy after one month of PBS immersion, demonstrating excellent stability. Overall, this single-molecule multifunctional strategy may become a promising surface engineering technique for blood-contacting materials.

Thrombosis and infection are pivotal clinical complications associated with interventional blood-contacting devices, leading to significant morbidity and mortality. To address these issues, we present a stepwise metal-catechol-(amine) (MCA) surface engineering strategy that efficiently integrates therapeutic nitric oxide (NO) gas and antibacterial peptide (ABP) onto catheters, ensuring balanced anti-thrombotic and anti-infective properties. First, copper ions were controllably incorporated with norepinephrine and hexanediamine through a one-step molecular/ion co-assembly process, creating a NO-generating and amine-rich MCA surface coating. Subsequently, azide-polyethylene glycol 4-N-hydroxysuccinimidyl and dibenzylcyclooctyne modified ABP were sequentially immobilized on the surface via amide coupling and bioorthogonal click chemistry, ensuring the dense grafting of ABP while maintaining the catalytic efficacy for NO. This efficient integration of ABP and NO-generating ability on the catheter surface provides potent antibacterial properties and ability to resist adhesion and activation of platelets, thus synergistically preventing infection and thrombosis. We anticipate that this synergistic modification strategy will offer an effective solution for advancing surface engineering and enhancing the clinical performance of biomedical devices.

Mesenchymal stem cells (MSCs) have demonstrated significant therapeutic potential in heart failure (HF) treatment. However, their clinical application is impeded by low retention rate and low cellular activity of MSCs caused by high inflammatory and reactive oxygen species (ROS) microenvironment. In this study, monascus pigment (MP) nanoparticle (PPM) was proposed for improving adverse microenvironment and assisting in transplantation of bone marrow-derived MSCs (BMSCs). Meanwhile, in order to load PPM and reduce the mechanical damage of BMSCs, injectable hydrogels based on Schiff base cross-linking were prepared. The PPM displays ROS-scavenging and macrophage phenotype-regulating capabilities, significantly enhancing BMSCs survival and activity in HF microenvironment. This hydrogel demonstrates superior biocompatibility, injectability, and tissue adhesion. With the synergistic effects of injectable, adhesive hydrogel and the microenvironment-modulating properties of MP, cardiac function was effectively improved in the pericardial sac of rats. Our results offer insights into advancing BMSCs-based HF therapies and their clinical applications.

Thrombosis and infection are two major complications associated with central venous catheters (CVCs), which significantly contribute to morbidity and mortality. Antifouling coating strategies currently represent an efficient approach for addressing such complications. However, existing antifouling coatings have limitations in terms of both duration and effectiveness. Herein, we propose a durable zwitterionic polymer armor for catheters. This armor is realized by pre-coating with a robust phenol-polyamine film inspired by insect sclerotization, followed by grafting of poly-2-methacryloyloxyethyl phosphorylcholine (pMPC) via in-situradical polymerization. The resulting pMPC coating armor exhibits super-hydrophilicity, thereby forming a highly hydrated shell that effectively prevents bacterial adhesion and inhibits the adsorption and activation of fibrinogen and platelets in vitro. In practical applications, the armored catheters significantly reduced inflammation and prevented biofilm formation in a rat subcutaneous infection model, as well as inhibited thrombus formation in a rabbit jugular vein model. Overall, our robust zwitterionic polymer coating presents a promising solution for reducing infections and thrombosis associated with vascular catheters.

Thrombus formation and tissue embedding significantly impair the clinical efficacy and retrievability of temporary interventional medical devices. Herein, we report an insect sclerotization-inspired antifouling armor for tailoring temporary interventional devices with durable resistance to protein adsorption and the following protein-mediated complications. By mimicking the phenol-polyamine chemistry assisted by phenol oxidases during sclerotization, we develop a facile one-step method to crosslink bovine serum albumin (BSA) with oxidized hydrocaffeic acid (HCA), resulting in a stable and universal BSA@HCA armor. Furthermore, the surface of the BSA@HCA armor, enriched with carboxyl groups, supports the secondary grafting of polyethylene glycol (PEG), further enhancing both its antifouling performance and durability. The synergy of robustly immobilized BSA and covalently grafted PEG provide potent resistance to the adhesion of proteins, platelets, and vascular cells in vitro. In ex vivoblood circulation experiment, the armored surface reduces thrombus formation by 95 %. Moreover, the antifouling armor retained over 60 % of its fouling resistance after 28 days of immersion in PBS. Overall, our armor engineering strategy presents a promising solution for enhancing the antifouling properties and clinical performance of temporary interventional medical devices.

Proteins, cells and bacteria adhering to the surface of medical devices can lead to thrombosis and infection, resulting in significant clinical mortality. Here, we report a zwitterionic polymers-armored amyloid-like protein surface engineering strategy we called as “armored-tank” strategy for dual functionalization of medical devices. The “armored-tank” strategy is realized by decoration of partially conformational transformed LZM (PCTL) assembly through oxidant-mediated process, followed by armoring with super-hydrophilic poly-2-methacryloyloxyethyl phosphorylcholine (pMPC). The outer armor of the “armored-tank” shows potent and durable zone defense against fibrinogen, platelet and bacteria adhesion, leading to long-term antithrombogenic properties over 14 days in vivowithout anticoagulation. Additionally, the “fired” PCTL from “armored-tank” actively and effectively kills both Gram-positive and Gram-negative bacterial over 30 days as a supplement to the lacking bactericidal functions of passive outer armor. Overall, this “armored-tank” surface engineering strategy serves as a promising solution for preventing biofouling and thrombotic occlusion of medical devices.

Control of premature corrosion of magnesium (Mg) alloy bioresorbable stents (BRS) is frequently achieved by the addition of rare earth elements. However, limited long-term experience with these elements causes concerns for clinical application and alternative methods of corrosion control are sought after. Herein, we report a “built-up” composite film consisting of a bottom layer of MgF2conversion coating, a sandwich layer of a poly (1, 3-trimethylene carbonate) (PTMC) and 3-aminopropyl triethoxysilane (APTES) co-spray coating (PA) and on top a layer of poly (lactic-co-glycolic acid) (PLGA) ultrasonic spray coating to decorate the rare earth element-free Mg–2Zn–1Mn (ZM21) BRS for tailoring both corrosion resistance and biological functions. The developed “built-up” composite film shows synergistic functionalities, allowing the compression and expansion of the coated ZM21 BRS on an angioplasty balloon without cracking or peeling. Of special importance is that the synergistic corrosion control effects of the “built-up” composite film allow for maintaining the mechanical integrity of stents for up to 3 months, where complete biodegradation and no foreign matter residue were observed about half a year after implantation in rabbit iliac arteries. Moreover, the functionalized ZM21 BRS accomplished re-endothelialization within one month.

We present a new data generation method to facilitate an automatic machine interpretation of 2D engineering part drawings. While such drawings are a common medium for clients to encode design and manufacturing requirements, a lack of computer support to automatically interpret these drawings necessitates part manufacturers to resort to laborious manual approaches for interpretation which, in turn, severely limits processing capacity. Although recent advances in trainable computer vision methods may enable automatic machine interpretation, it remains challenging to apply such methods to engineering drawings due to a lack of labeled training data. As one step toward this challenge, we propose a constrained data synthesis method to generate an arbitrarily large set of synthetic training drawings using only a handful of labeled examples. Our method is based on the randomization of the dimension sets subject to two major constraints to ensure the validity of the synthetic drawings. The effectiveness of our method is demonstrated in the context of a binary component segmentation task with a proposed list of descriptors. An evaluation of several image segmentation methods trained on our synthetic dataset shows that our approach to new data generation can boost the segmentation accuracy and the generalizability of the machine learning models to unseen drawings.

• By using building block properties of self-assembling peptides, a peptide-based NO-generating hydrogel coating is constructed for mimicking the functions of endothelium. • The developed peptide-based hydrogel coatings exhibit GPx-like activity to catalytically generate NO from endogenous s-nitrosothiols (RSNO), showing excellent anti-thrombogenic properties. • Such hydrogel coating provides a novel, facile and promising surface engineering platform for developing endothelium-mimicking devices. Thrombosis is the major stumbling block to the clinical application of blood-contacting devices. Herein, a quick and easy surface engineering strategy of hydrogel coating with the therapeutic gas nitric oxide (NO) generation was reported to realize up-regulation of cyclic guanosine monophosphate (cGMP) and improve hemocompatibility for diverse metal materials. We first introduce the active centre selenocysteine of glutathione peroxidase (GPx) to the self-assembling peptide (RADA) 4 , obtaining a functionalized hydrogel. Then the hydrogel is directly coated on the 316L stainless steel (SS) for catalytically generating NO from endogenous s-nitrosothiols (RSNO). The generated NO endows the coated surface with regulation of platelet behavior and reduction of plasmatic coagulation activation and complement system activation, hence improving antithrombotic ability in vitro and ex vivo. Overall, our NO-generating hydrogel coating surface engineering strategy provides a novel solution to remove the obstacle about thrombosis of blood-contacting devices in clinic. [Display omitted] [ABSTRACT FROM AUTHOR]

Universal coatings with versatile surface adhesion, good mechanochemical robustness, and the capacity for secondary modification are of great scientific interest. However, incorporating these advantages into a system is still a great challenge. Here, we report a series of catechol-decorated polyallylamines (CPAs), denoted as pseudo-Mytilus edulisfoot protein 5 (pseudo-Mefp-5), that mimic not only the catechol and amine groups but also the backbone of Mefp-5. CPAs can fabricate highly adhesive, robust, multifunctional polyCPA (PCPA) coatings based on synergetic catechol-polyamine chemistry as universal building blocks. Due to the interpenetrating entangled network architectures, these coatings exhibit high chemical robustness against harsh conditions (HCl, pH 1; NaOH, pH 14; H2O2, 30%), good mechanical robustness, and wear resistance. In addition, PCPA coatings provide abundant grafting sites, enabling the fabrication of various functional surfaces through secondary modification. Furthermore, the versatility, multifaceted robustness, and scalability of PCPA coatings indicate their great potential for surface engineering, especially for withstanding harsh conditions in multipurpose biomedical applications.

Appropriately adapted comprehensive mechanical properties, degradation behavior and biocompatibility are prerequisites for the application of Zn-based biodegradable implants. In this study, hot-extruded Zn–0.5Cu–xFe (x = 0.1, 0.2 and 0.4 wt%) alloys were fabricated as candidates for biodegradable materials for guided bone regeneration (GBR) membranes. The hot-extrusion process and Cu alloying were expected mostly to enhance the mechanical properties, and the Fe alloying was added mainly for regulating the degradation. The microstructure, mechanical properties and in vitrodegradation behavior were systematically investigated. The ZnCuFe alloys were composed of a Zn matrix and FeZn13phase. With increasing Fe content, a higher FeZn13phase precipitation with larger particles was observed. Since elongation declined significantly until fracture with increasing Fe content up to 0.4 wt%, the ZnCuFe (0.2 wt%) alloy achieved a good balance between mechanical strength and ductility, with an ultimate tensile strength of 202.3 MPa and elongation at fracture of 41.2%. Moreover, the addition of Fe successfully accelerated the degradation of ZnCuFe alloys. The ZnCuFe (0.2 wt%) alloy showed relatively uniform corrosion in the long-term degradation test. Furthermore, extracts of the ZnCuFe (0.2 wt%) alloy showed no apparent cytotoxic effects against L929 fibroblasts, Saos-2 osteoblasts or TAg periosteal cells. The ZnCuFe (0.2 wt%) alloy exhibited the potential to inhibit bacterial adhesion of Streptococcus gordoniiand mixed oral bacteria. Our study provides evidence that the ZnCuFe (0.2 wt%) alloy can represent a promising material for the application as a suitable GBR membrane.

Located in the inland arid area of Central Asia and northwest China, Xinjiang has recently received heightened concerns over soil water erosion, which is highly related with the sustainable utilization of barren soil and limited water resources. Data from the national soil erosion survey of China (1985–2011) and Xinjiang statistical yearbook (2000–2010) was used to analyze the trend, intensity, and serious soil water erosion regions. Results showed that the water erosion area in Xinjiang was 87.6×103km2in 2011, mainly distributed in the Ili river valley and the northern and southern Tian Mountain. Soil erosion gradient was generally slight and the average erosion modulus was 2184t/(km2a). During the last 26 years, the water erosion area in Xinjiang decreased by 23.2%, whereas the intensity was still increasing. The driving factors from large to small impact included: population boom and human activities>vegetation degradation>rainfall and climate change>topography and soil erodibility>tectonics movement. Soil water erosion resulted in eco-environmental and socioeconomic losses, such as destroying farmland and grassland, triggering floods, sedimentation of reservoirs, damaging transportation and irrigation facilities, and aggravating poverty. A landscape ecological design approach is suggested for integrated control of soil erosion. Currently, an average of 2.07×103km2of formerly eroded area is conserved each year. This study highlighted the importance and longevity of soil and water conservation efforts in Xinjiang, and offered some suggestions on ecological restoration and combating desertification in arid regions of Central Asia.

Soil pedons are commonly differentiated into a succession of horizons based on observable differences in soil color, texture, structure, or other characteristics, which are essentially associated with or determined by the chemical composition of soil materials. Portable X‐ray fluorescence spectrometry (PXRF), which provides scanning results in ∼60 to 90 s, offers a rapid means of quantifying elemental concentrations in the soil. This research evaluated the use of PXRF on 10 soil pedons in Louisiana for enhanced identification of soil horizons based on differences in elemental concentrations. Three quantifiable measures, difference of clay contents (DC), difference of laboratory analysis results (DLA), and difference of PXRF elemental concentrations (DE), were established based on principal component analysis for evaluating PXRF for soil horizonation. The results showed the variations of PXRF elemental concentrations (DE) in the pedons matched with described horizons better than those of laboratory (DLA) or clay (DC) measures in terms of horizon uniqueness. Furthermore, the PXRF scans conducted under field, lab, or monolith conditions achieved almost the same results. This will allow the use of PXRF as a means of discreetly differentiating elemental differences in archived monoliths with implications for adjustments to their taxonomic classification and land use recommendations. In summary, PXRF was shown to be an effective tool for enhanced soil horizon differentiation on alluvial soils in Louisiana.

Human-induced soil change is attracting increasing attention, yet how to quantitatively measure anthropogenic impact on changes in soil properties remains unclear. Eight selected soil properties—bulk density (BD), sand, silt, and clay content, pH, soil organic matter (SOM), total carbon (TC), and total nitrogen (TN)—at four soil depths (0–10, 10–20, 20–30, and 30–40 cm) were measured across three soil series (Gallion, Latanier and Sharkey) in south-central Louisiana, USA, to quantify changes in soil properties as a function of three contrasting land use types, i.e. forest, cropland, and Wetlands Reserve Program. Partial eta-squared values (η2) derived from two-way analysis of variance were used to quantitatively compare natural factors (soil series) and anthropogenic impact (land use) on these soil properties. Results showed that properties such as BD, pH, SOM, TC, and TN could be easily changed by anthropogenic disturbance, especially at 0–10 cm, while soil texture was mainly a natural factor. The anthropogenic factor accounted for 55.2%, 39.5%, 33.2%, and 36.0% of changes in the soil properties at 0–10, 10–20, 20–30, and 30–40 cm depth, respectively. These findings highlight the anthropogenic impact on selected soil properties.

The variation of soil organic carbon (SOC) concentration is important not only for indicating the uncertainty of SOC stock at spatial scales, but also for calculating the minimum sample size to detect SOC concentration change temporally. The coefficient of variation (CV), an index often used to express the variation of SOC concentration, is affected by multiple sampling factors. Yet, minimization of the SOC concentration CV remains elusive. A total of 117 observations of the CV for SOC concentration in croplands were collected from 41 published studies. Pearson correlation analysis was used to determine the effect of three sampling factors, that is, sample size, sampling area, and sampling interval, on SOC concentration variation. Results showed that the SOC concentration of croplands was mostly low (CV, <15%) to moderately (CV, 15%-35%) variable. Significant linear relationships existed between the CV and sample size, and between the CV and log (sampling area), suggesting that stratified sampling may reduce SOC variation. A significant linear relationship also existed between the CV and log (sampling interval), indicating that soil spatial variability contributed to the high CV of SOC concentration. A maximum of 2 km of sampling interval was recommended for SOC stock investigations in croplands. These findings provide some guidance for optimum sampling design on SOC dynamics research.

Zinc is becoming one of the leading candidate materials for biodegradable orthopedic implants owing to its attractive properties in terms of degradation behavior and mechanical properties. However, the insufficient surface bio-activities postpone its clinical application. In this study, an organic-inorganic collagen entrapped calcium/zinc phosphates coating was constructed on Zn surface to lessen Zn2+releasing rate and to leverage the surface osteogenic and angiogenic properties. Collagen molecules were immobilized onto Zn substrate and subsequently coordinated with calcium and zinc ions to promote the CaZnP inorganic phase growth, ensuing an intertwined collagen-CaZnP hybrid system. Consequently, the hybrid coating was highly coalesced and compact. Such high quality warranted the contained Zn2+releasing in a tolerable rate favorable for cells viability. The collagen-CaZnP coated Zn showed remarkedly stronger osteogenicity as compared to the untreated Zn, ascertained by the MC3T3-E1 osteoblast cell proliferation and differentiation assays, such as alkaline phosphatase expression and calcium nodule formation results. In addition, this hybrid coating supported human umbilical vein endothelial cells (HUVECs) migration and tube formation. The enhanced osteogenic and angiogenic properties could be ascribed to the nature of collagen and calcium/zinc phosphate components, the hybrid micro/nano-structure as well as the ability of controlling the Zn2+release of Zn substrate into a suitable concentration range. Our strategy provides a new avenue to surface modification of biodegradable metals for bone regenerative perspective.

The ability to track human operators' hand usage when working in production plants and factories is critically important for developing realistic digital factory simulators as well as manufacturing process control. We propose a proof-of-concept instrumented glove with only a few strain gage sensors and a microcontroller that continuously tracks and records the hand configuration during actual use. At the heart of our approach is a trainable system that can predict the fourteen joint angles in the hand using only a small set of strain sensors. First, ten strain gages are placed at various joints in the hand to optimize the sensor layout using the English letters in the American Sign Language (ASL) as a benchmark for assessment. Next, the best sensor configurations for three through ten strain gages are computed using a support vector machine (SVM) classifier. Following the layout optimization, our approach learns a mapping between the sensor readouts to the actual joint angles optically captured using a Leap Motion system. Five regression methods including linear, quadratic, and neural regression are then used to train the mapping between the strain gage data and the corresponding joint angles. The final proposed model involves four strain gages mapped to the fourteen joint angles using a two-layer feed-forward neural network (NN).

The access position and capacity of distribution generation (DG) affect the static voltage stability of micro-grid, thus affecting the renewable energy utilization. In the current reform of the energy supply side, a multi-objective optimization model is established, aiming at the abandoning wind and abandoning light problem. This model has three advantages, which are the largest renewable energy utilization, static voltage stability of micro-grid and the minimum cost of DG investment considering environmental benefits. It can effectively promote the use of wind power, photovoltaic power generation and other renewable energy sources. In this paper, the multi-objective optimization problem is transformed into a single objective programming problem by using the deviation method; the optimal solution of multi-objective function is solved by using particle swarm optimization algorithm, so as to establish the planning scheme of micro-grid. Simulation results prove the correctness and feasibility of the optimization method.