Interactions of graphene with oxidants in a mixed atmosphere: synergistic effects of O2/H2O and O2/CO2 on gasification reactivity and kinetics.

The gasification of carbon with O2, CO2, and H2O oxidants plays an important role in several energy-based applications. As most of the industrial gasification processes are conducted under mixed-atmosphere conditions, the oxidation of carbon in binary oxidant mixtures becomes crucially important. Using reactive force-field (ReaxFF) potentials, extensive MD simulations were carried out on the oxidation behavior of graphene in mixed O2/H2O and O2/CO2 environments for a range of gas compositions and temperatures. A graphene sheet with a line defect comprising of eight and four-membered rings was used as the starting carbon structure. In addition to enhanced carbon gasification with oxygen additions, MD simulations showed synergistic interactions between different oxidants and their net influence on the overall reactivities. The gasification levels achieved under the binary system were higher than the linear combination of contributions from individual oxidants. The addition of ∼40% O2 in the binary mix was identified as the region with the highest reactivity during the initial stages of gasification. The oxidation reactions with oxygen were found to start instantaneously in the presence of H2O or CO2 instead of the usual initial delay. A very fast reaction kinetics was also observed in the initial stages in the presence of oxygen. Our results show that the gasification reactions under H2O and CO2 started at lower temperatures than O2 thereby creating a partially oxidized structure. Due to the presence of a large number of activation sites, very high rates of gasification were achieved with oxygen. These findings could help identify optimal oxidant compositions towards maximizing carbon gasification and minimizing CO2 emissions.

The Adsorption Behaviors of CO and H2 to FeO onto CaO Surfaces: A Density Functional Theory Study.

The adsorption behaviors of CO and H2 to FeO onto CaO surfaces have been studied using the density functional theory (DFT) to determine the reactions of FeO by CO and H2. The adsorption mechanisms of FeO clusters on the CaO(100) and CaO(110) surfaces were calculated first. The structure of the Ca(110) surface renders it highly chemically reactive compared with the Ca(100) surface because of low coordination. After gas adsorption, CO bonds to the O atom of FeO, forming CO2 compounds in both configurations through the C atom. H2 favors the O atom of FeO, forming H2O compounds and breaking the Fe-O bond. Comparing the adsorption behavior of two reducing gases to FeO on the Ca surface, the reaction of the CO molecule being adsorbed to generate CO2 compounds is exothermic. The reaction of H2 molecule adsorption to generate H2O compounds is endothermic. This property is essential for the inertial-collision stage of the reduction. However, the dissociation of the CO2 compound from the reaction interface will overcome a high energy barrier and slow down the reduction. The H2O compound dissociates from the surface more easily, which can accelerate the reduction.

Adsorption and reaction mechanisms of single and double H2O molecules on graphene surfaces with defects: a density functional theory study.

More attention needs to be drawn to the high application value of the gasification reaction between carbonaceous materials and water in industry. In this study, density functional theory is used to investigate the adsorption and reaction mechanism of water molecules on graphene surfaces with various kinds of defects. The desorption mechanism of the reaction product is also analyzed. The optimal and stable physical adsorption configuration of water molecules on the pristine graphene and various defects graphene surface has been determined. Chemisorption configurations of a single water molecule and double water molecules on the graphene surface with single vacancy defects are discussed and used as reaction precursors to explore the reaction path of water molecules in the process of desorbing hydrogen at active sites. The whole process of the reaction is largely exothermic and the thermodynamic advantages of double water molecules participating in the reaction are determined. The two reaction mechanisms of two-steps or co-adsorption and desorption of double water molecules are compared, and the lowest energy barrier advantage of the latter is determined.

Developments in Atomistic and Nano Structure Evolution Mechanisms of Molten Slag Using Atomistic Simulation Methods.

Molten slag has different properties depending on its composition. The relationship between its composition, structure, and properties has been the focus of attention in industrial manufacturing processes. This review describes the atomistic scale mechanisms by which oxides of different compositions affect the properties and structure of slag, and depicts the current state of research in the atomic simulation of molten slag. At present, the research on the macroscopic properties of molten slag mainly focuses on viscosity, free-running temperature, melting point, and desulphurization capacity. Regulating the composition has become the most direct and effective way to control slag properties. Analysis of the microevolution mechanism is the fundamental way to grasp the macroscopic properties. The microstructural evolution mechanism, especially at the atomic and nanoscale of molten slag, is reviewed from three aspects: basic oxides, acidic oxides, and amphoteric oxides. The evolution of macroscopic properties is analyzed in depth through the evolution of the atomic structure. Resolution of the macroscopic properties of molten slag by the atomic structure plays a crucial role in the development of fundamental theories of physicochemistry.

The Dynamic Nature of Graphene Active Sites in the H2O Gasification process: A ReaxFF and DFT Study.

CONTEXT: A steam-rich environment is a more promising application scenario for future coal-fired processes, while active sites are the key factor that determines the reactivity of carbonaceous fuels. The steam gasification process of carbon surfaces with different numbers of active sites (0, 12, 24, 36) was simulated using reactive molecular dynamics in the present study. The temperature for the decomposition of H2O and the gasification of carbon is determined using temperature-increasing simulation. The decomposition of H2O was influenced by two driving forces, thermodynamics and active sites on the carbon surface, which dominated the different reaction stages, leading to the observed segmentation phenomenon of the H2 production rate. The existence and number of initial active sites have a positive correlation with both two stages of the reaction, greatly reducing the activation energy. Residual OH groups play an important role in the gasification of carbon surfaces. The supply of OH groups through the cleavage of OH bonds in H2O is the rate-limiting step in the carbon gasification reaction. The adsorption preference at carbon defect sites was calculated using density functional theory. Two stable configurations (ether & semiquinone groups) can be formed with O atoms adsorbed on the carbon surface according to the number of active sites. This study will provide further insights into the tuning of active sites for advanced carbonaceous fuels or materials. METHODS: The large-scale atomic/molecule massively parallel simulator (LAMMPS) code combined with the reaction force-field method was used to carry out the ReaxFF molecular dynamics simulation, where the ReaxFF potentials were taken from Castro-Marcano, Weismiller and William. The initial configuration was built using Packmol, and the visualization of the calculation results was realized through Visual Molecular Dynamics (VMD). The timestep was set to 0.1 fs to detect the oxidation process with high precision. PWscf code in QUANTUM ESPRESSO (QE) package, was used to evaluate the relative stability of different possible intermediate configurations and the thermodynamic stability of gasification reactions. The projector augmented wave (PAW) and the generalized gradient approximation of Perdew-Burke-Ernzerhof (PBE-GGA) were adopted. Kinetic energy cutoffs of 50 Ry and 600 Ry, and a uniform mesh of 4 × 4 × 1 k-points were used.

Ab Initio Investigation of the Adsorption of CO2 Molecules on Defect Sites of Graphene Surfaces: Role of Local Vacancy Structures.

An in-depth investigation into the adsorption of CO2 on graphene vacancies is essential for the understanding of their applications in various industries. Herein, we report an investigation of the effects of vacancy defects on CO2 gas adsorption behavior on graphene surfaces using the density functional theory. The results show that the formation of vacancies leads to various deformations of local carbon structures, resulting in different adsorption capabilities. Even though most carbon atoms studied can only trigger physisorption, there are also carbon sites that are energetically favored for chemisorption. The general order of the adsorption capabilities of the local carbon atoms is as follows: carbon atoms with dangling bonds > carbon atoms shared by five- and six-membered rings and a vacancy > carbon atoms shared by two six-membered rings and a vacancy. A stronger interaction in the adsorption process generally corresponds to more obvious changes in the partial density of states and a larger amount of transferred charge.

Effect of Different sp2 Bond Contents on the Reactivity and Mechanical Properties of Coke Carbon: A ReaxFF Molecular Dynamics Study.

In this study, ReaxFF-MD was used to construct a large-molecule model of coke containing 3000 atoms, and the sp2 bond content of the model was controlled by changing the heating and cooling rates. The increase of the sp2 bond content led to a significant difference in the reactivity of coke. The presence of the sp2 bond caused the carbon atoms inside the coke to change into a circular structure, making it more difficult for the gaseous atoms to adsorb on the surface of the coke. It significantly reduced the gasification reaction rate of coke in the CO2 and H2O atmospheres. In the tensile simulation experiment, it was found that the stretching process of coke was mainly divided into three stages: an elastic stretching stage, a plastic stretching stage, and a model fracture stage. During the stretching process, the carbon ring structure would undergo a C-C bond fracture while generating carbon chains to resist stress. The results indicated that the presence of sp2 bonds can effectively reduce the phenomenon of excessive local stress on coke to improve its tensile resistance. The method developed in this paper may provide further ideas and platforms for the research on coke performance.

The Adsorption Mechanism of Hydrogen on FeO Crystal Surfaces: A Density Functional Theory Study.

The hydrogen-based direct reduction of iron ores is a disruptive routine used to mitigate the large amount of CO2 emissions produced by the steel industry. The reduction of iron oxides by H2 involves a variety of physicochemical phenomena from macroscopic to atomistic scales. Particularly at the atomistic scale, the underlying mechanisms of the interaction of hydrogen and iron oxides is not yet fully understood. In this study, density functional theory (DFT) was employed to investigate the adsorption behavior of hydrogen atoms and H2 on different crystal FeO surfaces to gain a fundamental understanding of the associated interfacial adsorption mechanisms. It was found that H2 molecules tend to be physically adsorbed on the top site of Fe atoms, while Fe atoms on the FeO surface act as active sites to catalyze H2 dissociation. The dissociated H atoms were found to prefer to be chemically bonded with surface O atoms. These results provide a new insight into the catalytic effect of the studied FeO surfaces, by showing that both Fe (catalytic site) and O (binding site) atoms contribute to the interaction between H2 and FeO surfaces.

The evolution of atomistic structure and mechanical property of coke in the gasification process with CO2 and H2O at different temperatures: A ReaxFF molecular dynamics study.

CONTEXT: An atomistic coke carbon model was constructed to simulate the structural evolution in the gasification and stretching process. The coke model was placed in a box with different CO2/H2O content to investigate the evolution of the atomistic structure of coke during the gasification. It was found that different atmospheric concentrations had different effects on the structure and reaction sites of the coke model. The CO2 molecules tended to dissolve on the surface of coke and disrupt its surface structure, while H2O molecules were more likely to enter the coke model to disrupt the internal structure. For tensile simulation, it was found that CO2 and H2O had different effects on the tensile resistance of the coke model. Controlling the composition content of the reaction gas can effectively influence the tensile strength of the coke model. By revealing the behavior of coke model at the micro scale, it provides a theoretical basis for the industrial coke application process. METHODS: Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) was used to conduct the molecular dynamics using the reactive force field (ReaxFF). The atomistic model of coke carbon was constructed using the well-known annealing and quenching method, and its composition is determined according to the element analysis of industrial coke. The structural evolution in the gasification with CO2/H2O and the stretching process were analyzed in detail. Molecular dynamics simulations with reactive force field (ReaxFF-MD) were used to simulate the coke dissolution reaction under CO2/H2O atmosphere and the coke stretching process. The atmosphere ratio was modified to investigate the changes in coke structure under different atmosphere conditions. The Packmol software was used to place gas and coke models into the same box. During the reaction process, the Ovito software was used to perform corresponding visualization analysis on the changes in the atomic structure of coke.

A reactive molecular dynamics study of thermal pyrolysis behavior and mechanisms of lignin during the hydrothermal process: The function of the water molecules.

The lignin hydrothermal processing is an important option but a full understanding of the role played by the water molecules in the depolymerization of lignin is still lacking. In order to clarify the role of the water molecules in the depolymerization of lignin, the evolution of chemical bonds, microstructural changes, and possible mechanisms of product generation were compared during the pyrolysis process under vacuum and water conditions using Reactive Molecular Dynamics Simulation. Compared with vacuum conditions, the role of water changes with temperature, identifying three stages: promotion (1200-1800 K)-inhibition (2100-2400 K)-promotion (2700-3000 K). Also compared with vacuum conditions, hydrothermal processing can promote the cleavage of the ether bonds while inhibiting the destruction of carbocycles. Water molecules promote the depolymerization of lignin into more C4-molecules, thereby generating more combustible gas resources. Based on the research results, the pyrolysis conditions of lignin can be flexibly controlled to obtain solids, liquids or gases.

Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel.

Iron making is the biggest single cause of global warming. The reduction of iron ores with carbon generates about 7% of the global carbon dioxide emissions to produce ≈1.85 billion tons of steel per year. This dramatic scenario fuels efforts to re-invent this sector by using renewable and carbon-free reductants and electricity. Here, the authors show how to make sustainable steel by reducing solid iron oxides with hydrogen released from ammonia. Ammonia is an annually 180 million ton traded chemical energy carrier, with established transcontinental logistics and low liquefaction costs. It can be synthesized with green hydrogen and release hydrogen again through the reduction reaction. This advantage connects it with green iron making, for replacing fossil reductants. the authors show that ammonia-based reduction of iron oxide proceeds through an autocatalytic reaction, is kinetically as effective as hydrogen-based direct reduction, yields the same metallization, and can be industrially realized with existing technologies. The produced iron/iron nitride mixture can be subsequently melted in an electric arc furnace (or co-charged into a converter) to adjust the chemical composition to the target steel grades. A novel approach is thus presented to deploying intermittent renewable energy, mediated by green ammonia, for a disruptive technology transition toward sustainable iron making.

A density functional theory study on the adsorption reaction mechanism of double CO2 on the surface of graphene defects.

Much research has been done on reactions of a single CO2 molecule with a graphene surface. In this paper, density functional theory calculations are used to investigate the adsorption and reaction of double CO2 on the surface of single vacancy (SV) and divacancy (DV) defect graphene. The study found that due to the mutual repulsion between CO2 and the size of the SV defect, it is difficult for two CO2 molecular to be adsorbed directly above the SV defect at the same time. Regardless of SV or DV, the adsorption of the first CO2 in the defect center will have a beneficial effect on the adsorption of the second CO2. In addition, the transition state calculation of the CO2 reaction on the DV plane was carried out, and the adsorption behavior was analyzed and studied. This in-depth study is helpful to the understanding of the reaction behavior of CO2 on graphene, and further exploration in the direction of the effective application of graphene to the reaction and adsorption of CO2. Our work explores the adsorption behavior of CO2 on graphene surfaces, the physical and chemical adsorption of double CO2 at the defect was studied and analyzed.

Density Functional Studies on the Atomistic Structure and Properties of Iron Oxides: A Parametric Study.

With the aim to find the best simulation routine to accurately predict the ground-state structures and properties of iron oxides (hematite, magnetite, and wustite) using density functional theory (DFT) with Hubbard-U correction, a significant amount of DFT calculations were conducted to investigate the influence of various simulation parameters (energy cutoff, K-point, U value, magnetization setting, smearing value, etc.) and pseudopotentials on the structures and properties of iron oxides. With optimized simulation parameters, the obtained equation of state, lattice constant, bulk moduli, and band gap is much closer to the experimental values compared with previous studies. Due to the strong coupling between the 2p orbital of O and the 3d orbital of Fe, it was found that Hubbard-U correction obviously improved the results for all three kinds of iron oxides including magnetite which has not yet been tested with U correction before, but the U value should be different for different oxides (3 ev, 4 ev, 4 ev for hematite, magnetite, and wustite, respectively). Two kinds of spin magnetism settings for FeO are considered, which should be chosen according to different calculation purposes. The detailed relationship between the parameter settings and the atomic structures and properties were analyzed, and the general principles for future DFT calculation of iron oxides were provided.

Preparation and antibacterial properties of an AgBr@SiO2/GelMA composite hydrogel.

Pure gelatin hydrogels lack antibacterial function and have poor mechanical properties, which restrict their application in wound dressings. In this study, nanosized silver bromide-doped mesoporous silica (AgBr@SiO2) microspheres with hollow structures were prepared by a modified Stober method. The novel microspheres can not only release silver ions to treat bacteria but also release drugs to treat skin wound. Furthermore, AgBr@SiO2microspheres were modified with propyl methacrylate, incorporated into methacrylated gelatin (GelMA), and crosslinked by UV light to prepare AgBr@SiO2/GelMA dressings consisting of composite hydrogels. The results showed that the AgBr@SiO2microspheres could enhance the mechanical properties of the hydrogels. With the increase in the AgBr@SiO2concentration from 0.5 to 1 mg ml-1, the dressings demonstrated effective antimicrobial activity against bothStaphylococcus aureusandEscherichia coli. Furthermore, full-thickness skin woundsin vivowound healing studies with Sprague-Dawley rats were evaluated. When treated with AgBr@SiO2/GelMA containing 1 mg ml-1AgBr@SiO2, only 15% of the wound area left on day 10. Histology results also showed the epidermal and dermal layers were better organized. These results suggest that AgBr@SiO2/GelMA-based dressing materials could be promising candidates for wound dressings.

New Insights into the Traditional Charge Compensation Theory: Amphoteric Behavior of TiO2 under the Guidance of Supply-Demand Relationship.

Polymerization degree theory and traditional charge compensation theory are the most fundamental principles to understand the structure and properties of oxide melts. It can well explain the behavior characteristics of acidic oxides and basic oxides in a melt. However, the amphoteric behavior of oxides cannot be explained well by these two theories. Herein, the octahedral connection mode and the behavior of the amphoteric transition of TiO2 are analyzed by molecular dynamics simulation, and then, a calculation model which can quantitatively calculate the amphoteric transition of the oxide is established by analyzing a large number of data. On the basis of the model, a novel theory of supply and demand is put forward, which can explain the amphoteric transition behavior of oxides very well. To a great extent, the supply and demand theory makes up for the deficiency of the atomic structure theory of oxide melts and provides mechanism explanation and model prediction for the oxide amphoteric transformation behavior.

[Effects of brackish water irrigation on grain quality characteristics and yield of winter wheat]. / 咸水灌溉对冬小麦籽粒品质特性和产量的影响.

Brackish water resource is widely distributed in the North China Plain, which has not been effectively utilized. Using brackish water for irrigation can alleviate water resource conflict in the well-irrigated area and solve the problem of groundwater over-exploitation of the North China Plain. A long-term experiment (since 2006) was conducted to investigate the effects of brackish water irrigation on the quality and yield of winter wheat in the North China Plain. There were five salinity degrees of irrigation water, i.e. 1, 2, 4, 6, and 8 g·L-1, respectively. The results showed that higher salinity degree of irrigation water (4-8 g·L-1) significantly increased water absorption, development time, sedimentation, wet gluten content, and protein content, but decreased the stabilization time, flour yield, and gluten index. There was no significant difference between the treatments of 1 g·L-1 and 2 g·L-1 on grain yield and yield components, but the treatment of 2 g·L-1 significantly improved grain quality, including water absorption, development time, sedimentation, wet gluten, and protein content. Higher salinity degree of irrigation water (4-8 g·L-1) treatments significantly decreased spike number (44.0%-60.7%) and grain yield (35.6%-64.7%), compared with 1 g·L-1 treatment. Results of principal component analysis showed that 2 g·L-1 treatment had the best overall effect with no significant decrease in grain yield and quality of grain. This study could provide theoretical basis and technical support for use of brackish water in the North China Plain.

[Effects of saline-water furrow irrigation on the stability of soil water-stable aggregates in cotton field]. / 咸水沟灌对棉田土壤水稳性团聚体稳定性的影响.

It is of great importance to explore the effects of saline-water furrow irrigation on soil water-stable aggregates for safe and efficient utilization of saline water resources. We conducted a long-term cotton experiment with six levels of saline-water furrow irrigation (1, 2, 4, 6, 8, 10 g·L-1) since 2006 and analyzed the variations of soil salinity and water-stable aggregates in the 10th and 15th years under saline irrigation. The results showed that soil salinity in the 0-30 cm layer at the ditch increased with increasing salinity level of irrigation water. There were significant differences between the 6, 8, 10 g·L-1 and 1 g·L-1 treatments. Soil salinity in each treatment increased gradually with increasing soil depth. Saline-water furrow irrigation tended to reduce the stability of soil water-stable aggregates. When the salinity level of the irrigation water was ≥6 g·L-1, the mass fraction of macroaggregates (>0.25 mm), the mean weight diameter and geometric mean diameter of water-stable aggregates significantly decreased. In contrast, the fractal dimension and mean weight specific surface area increased significantly. The stability of soil water-stable aggregates decreased with soil depth in all treatments. Under the condition of saline-water furrow irrigation for several years, there was no accumulation of soil salinity and instability of water-stable aggregates in the 0-30 cm soil layer at the ditch with each passing year. With the irrigation scheduling of this study, saline-water furrow irrigation with salinity ≤4 g·L-1 did not affect soil salinity and water-stable aggregate stability of cotton field in this area.

Cell-laden interpenetrating network hydrogels formed from methacrylated gelatin and silk fibroin via a combination of sonication and photocrosslinking approaches.

The regeneration of load-bearing soft tissues has long driven the research and development of bioactive hydrogels. A major challenge facing the application of hydrogels to load-bearing tissues is the development of hydrogels with appropriate biological functionality and biomechanical stability that closely mimic the host tissue. In this paper, we describe a newly synthesized cell-laden interpenetrating polymer network (IPN) hydrogel based on gelatin methacrylate (GelMA) and silk fibroin (SF) that was formed via sequential sonication and photocrosslinking. The experimental results revealed that SF-GelMA IPN hydrogels exhibited high swelling ratios, excellent mechanical properties, resistance to enzymatic degradation by collagenase, and porous internal microstructures. Moreover, these properties could be tailored by changing the prepolymer components. MC3T3-E1 pre-osteoblasts attached to and subsequently proliferated on the IPN hydrogels, as demonstrated by fluorescein diacetate/propidium iodide (FDA/PI) staining and Cell Counting Kit-8 (CCK-8) analysis. In addition, the encapsulation of MC3T3-E1 pre-osteoblasts and a subsequent cell viability assay demonstrated that the entire IPN formation process was compatible with cells and that the growth of encapsulated cells could be tuned by adjusting the GelMA concentration, underlining their versatility for various load-bearing soft tissue engineering. Overall, this study introduces a class of mechanically robust and tunable cell-laden IPN hydrogels which have great potential as load-bearing soft tissue engineering scaffold.

ReaxFF Molecular Dynamics Simulation for the Graphitization of Amorphous Carbon: A Parametric Study.

A parametric study of ReaxFF for molecular dynamics simulation of graphitization of amorphous carbon was conducted. The responses to different initial amorphous carbon configurations, simulation time steps, simulated temperatures, and ReaxFF parameter sets were investigated. The results showed that a time step shorter than 0.2 fs is sufficient for the ReaxFF simulation of carbon using both Chenoweth 2008 and Srinivasan 2015 parameter sets. The amorphous carbon networks produced using both parameter sets at 300 K are similar to each other, with the first peak positions of pair distribution function curves located between the graphite sp2 bond peak position and the diamond sp3 bond peak position. In the graphitization process, the graphene fragment size increases and the orientation of graphene layers transforms to be parallel with each other with the increase of temperature and annealing time. This parallel graphene structure is close to the crystalline graphite. Associated with this graphitization is the presence of small voids and pores which arise because of the more efficient atomic packing relative to a disordered structure. For all initial densities, both potential parameter sets exhibit the expected behavior in which the sp2 fraction increases significantly over time. The sp2 fraction increases with increasing temperature. The differences of sp2 fraction at different temperatures are more obvious in lower density at 1.4 g/cm3. When density is increased, the gap caused by different temperatures becomes small. This study indicates that both Chenoweth 2008 and Srinivasan 2015 potential sets are appropriate for molecular dynamics simulations in which the growth of graphitic structures is investigated.

Is insulin-like growth factor binding protein 2 associated with metastasis in lung cancer?

Insulin-like growth factor binding protein 2 (IGFBP2) is involved in the progression of many epithelial cancers. However, its role in non-small cell lung cancer (NSCLC), another type of epithelial cancer, remains unclear. We detected IGFBP2 expression using immunohistochemistry in surgically resected tumors from 110 NSCLC patients, 37 of which had metastases. The positive rate of IGFBP2 expression was compared between the metastatic and the non-metastatic group, and correlations of IGFBP2 expression with metastasis and overall survival were analyzed. We also investigated the expression of IGFBP2 in microvesicles (MVs) collected from primary lung cancer cell cultures, and in different locations of newly resected NSCLC tumors, using immunoblotting. The overall positive rate of IGFBP2 expression in lung cancer was 51.8 % and it was significantly higher in the metastatic group than in the non-metastatic group (70.3 and 42.5 % respectively, p < 0.01). And the higher the lymph node stage, the higher the positive rate. Cytoplasmic expression was predominant in the majority of the tumors. Based on multivariate regression analysis, IGFBP2 was correlated with metastasis and poor overall survival (Hazard ratio: 3.56 and 3.23 respectively). IGFBP2 was detectable in the MVs collected from IGFBP2 positive cell lines, and its expression was most abundant in the marginal region of the newly resected tumors. IGFBP2 is associated with metastasis and poor survival of lung cancer. Its presence in MVs and high abundance in the marginal region of tumors suggest that its association with metastasis may be related to tumor microenviroment remodeling in NSCLC.