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Density functional theory (DFT) has been established as a powerful research tool for heterogeneous catalysis research in obtaining key thermodynamic and/or kinetic parameters like adsorption energies, enthalpies of reaction, activation barriers, and rate constants. Understanding of density functional exchange-correlation approximations is essential to reveal the mechanism and performance of a catalyst. In the present work, we reported the influence of six exchange-correlation density functionals, including PBE, RPBE, BEEF+vdW, optB86b+vdW, SCAN, and SCAN+rVV10, on the adsorption energies, reaction energies and activation barriers of carbon hydrogenation and carbon-carbon couplings during the formation of methane and ethane over Ru(0001) and Ru([Formula: see text]) surfaces. We found the calculated reaction energies are strongly dependent on exchange-correlation density functionals due to the difference in coordination number between reactants and products on surfaces. The deviation of the calculated elementary reaction energies can be accumulated to a large value for chemical reaction involving multiple steps and vary considerably with different exchange-correlation density functionals calculations. The different exchange-correlation density functionals are found to influence considerably the selectivity of Ru(0001) surface for methane, ethylene, and ethane formation determined by the adsorption energies of intermediates involved. However, the influence on the barriers of the elementary surface reactions and the structural sensitivity of Ru(0001) and Ru([Formula: see text]) are modest. Our work highlights the limitation of exchange-correlation density functionals on computational catalysis and the importance of choosing a proper exchange-correlation density functional in correctly evaluating the activity and selectivity of a catalyst.

Despite the extensive study of the Fe-based Fischer–Tropsch synthesis (FTS) over the past 90 years, its active phases and reaction mechanisms are still unclear due to the coexistence of metals, oxi...

Considerable attention has been drawn to tune the geometric and electronic structure of interfacial catalysts via modulating strong metal-support interactions (SMSI). Herein, we report the construction of a series of TiO2−x/Ni catalysts, where disordered TiO2−x overlayers immobilized onto the surface of Ni nanoparticles (~20 nm) are successfully engineered with SMSI effect. The optimal TiO2−x/Ni catalyst shows a CO conversion of ~19.8% in Fischer–Tropsch synthesis (FTS) process under atmospheric pressure at 220 °C. More importantly, ~64.6% of the product is C2+ paraffins, which is in sharp contrast to the result of the conventional Ni catalyst with the main product being methane. A combination study of advanced electron microscopy, multiple in-situ spectroscopic characterizations, and density functional theory calculations indicates the presence of Niδ−/TiO2−x interfacial sites, which could bind carbon atom strongly, inhibit methane formation and facilitate the C-C chain propagation, lead to the production of C2+ hydrocarbon on Ni surface.

Ruthenium (Ru) serves as a promising catalyst for ammonia synthesis via the Haber-Bosch process, identification of the structure sensitivity to improve the activity of Ru is important but not fully explored yet. We present here density functional theory calculations combined with micro-kinetic simulations on nitrogen molecule activation, a crucial step in ammonia synthesis, over a variety of hexagonal close-packed (hcp) and face-center cubic (fcc) Ru facets. Hcp {213¯0} facet exhibits the highest activity toward N2 dissociation in hcp Ru, followed by the (0001) monatomic step sites. The other hcp Ru facets have N2 dissociation rates at least three orders lower. Fcc {211} facet shows the best performance for N2 activation in fcc Ru, followed by {311}, which indicates stepped surfaces make great contributions to the overall reactivity. Although hcp Ru {213¯0} facet and (0001) monatomic step sites have lower or comparable activation barriers compared with fcc Ru {211} facet, fcc Ru is proposed to be more active than hcp Ru for N2 conversion due to the exposure of the more favorable active sites over step surfaces in fcc Ru. This work provides new insights into the crystal structure sensitivity of N2 activation for mechanistic understanding and rational design of ammonia synthesis over Ru catalysts.

Strong metal-support interactions (SMSI) is an important concept in heterogeneous catalysis. Herein, we demonstrate that the Au-TiO2 SMSI of Au/TiO2 catalysts sensitively depends on both Au nanoparticle (NP) sizes and TiO2 facets. Au NPs of ca. 5 nm are more facile undergo Au-TiO2 SMSI than those of ca. 2 nm, while TiO2 {001} and {100} facets are more facile than TiO2 {101} facets. The resulting capsulating TiO2-x overlayers on Au NPs exhibit an average oxidation state between +3 and +4 and a Au-to-TiO2-x charge transfer, which, combined with calculations, determines the Ti:O ratio as ca. 6:11. Both TiO2-x overlayers and TiO2-x -Au interface exhibit easier lattice oxygen activation and higher intrinsic activity in catalyzing low-temperature CO oxidation than the starting Au-TiO2 interface. These results advance fundamental understanding of SMSI and demonstrate engineering of metal NP size and oxide facet as an effective strategy to tune the SMSI for efficient catalysis.

Sintering inhibition of a catalyst at high temperatures is a challenge during heterogeneous catalysis. In this paper, we report that hexagonal boron nitride (h-BN) is an optimal material for anti-sintering γ-Al2O3-supported Pt nanoparticles (NPs) originating from the high thermal conductivity of h-BN. The high thermal conductivity of h-BN ensures maximal heat dissipation from Pt NPs to γ-Al2O3, thereby causing both Ostwald ripening and particle coalescence of Pt NPs to be decelerated at elevated temperatures. Inhibition of Pt NP sintering is also shown in the reducible TiO2-supported Pt NPs with the help of h-BN. The proposed anti-sintering strategy using thermal management is universal, providing new insight into the design of anti-sintering materials and structures for a wide range of applications in heterogeneous catalysis.

Atomically dispersed metal catalysts with high atomic utilization and selectivity have been widely studied for acetylene semi-hydrogenation in excess ethylene among others. Further improvements of activity and selectivity, in addition to stability and loading, remain elusive due to competitive adsorption and desorption between reactants and products, hydrogen activation, partial hydrogenation etc. on limited site available. Herein, comprehensive density functional theory calculations have been used to explore the new strategy by introducing an appropriate ligand to stabilize the active single atom, improving the activity and selectivity on oxide supports. We find that the hydroxyl group can stabilize Ni single atoms significantly by forming Ni1(OH)2 complexes on anatase TiO2(101), whose unique electronic and geometric properties enable high performance in acetylene semi-hydrogenation. Specifically, Ni1(OH)2/TiO2(101) shows favorable acetylene adsorption and promotes the heterolytic dissociation of H2 achieving high catalytic activity, and it simultaneously weakens the ethylene bonding to facilitate subsequent desorption showing high ethylene selectivity. Hydroxyl stabilization of single metal atoms on oxide supports and promotion of the catalytic activity are sensitive to transition metal and the oxide supports. Compared to Co, Rh, Ir, Pd, Pt, Cu, Ag and Au, and anatase ZrO2, IrO2 and NbO2 surfaces, the optimum interactions between Ni, O and Ti and resulted high activity, selectivity and stability make Ni1(OH)2/TiO2(101) a promising catalyst in acetylene hydrogenation. Our work provides valuable guidelines for utilization of ligands in the rational design of stable and efficient atomically dispersed catalysts., Hydroxyl group can stabilize significantly Ni single atom by forming Ni1(OH)2 complexes on anatase TiO2(101), which displays high catalytic performance in acetylene semi-hydrogenation.

An active and stable bi-functional catalyst for the hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) is highly desirable for clean energy conversion devices, such as anion exchange membrane fuel cells (AEMFCs) and magnesium (Mg)–seawater batteries. Herein, DFT analysis predicates that the amine-ligand modulation manipulates the d-band center of ruthenium (Ru) downshift from the Fermi level, resulting in optimized hydrogen and hydroxide bonding energies (HBE and OHBE), and thus lowering the limiting energy of the HOR/HER. We elaborately fabricate NH2-ligand modulated Ru nanoclusters (Ru/PEI-XC), taking advantage of the abundant –NH2 groups of polyethylene imine (PEI). The optimal Ru/PEI-XC catalyst exhibits a superior HOR activity of 423.3 A gmetal−1 at an overpotential (η) of 50 mV and a specific exchange current density of 687.1 μA cmmetal−2, which are about 1.7 and 3.6 fold those of the commercial Pt/C catalyst. Ru/PEI-XC presents an overwhelming advantage for the HER in a wide pH range, especially in alkaline electrolyte, with η = 13 mV at −10 mA cm−2, which is 20 mV lower than that of Pt/C. Both the potentiostatic and accelerated degradation tests manifest the excellent long-term stability of Ru/PEI-XC in catalyzing the HOR and HER. Furthermore, Ru/PEI-XC as the anode of an AEMFC delivers a peak power density of 1.4 W mgPGM−1, comparable with that of its Pt/C-based counterpart. A proof-of-concept rechargeable Mg–seawater battery could also be driven by the Ru/PEI-XC cathode, delivering a maximum discharging power density of 18.9 mW cm−2, with low charging voltage and good cycling properties. This study reveals that ligand modulation is an effective strategy to manipulate the d-band center of metals and tune the reactivity, which paves an avenue for designing advanced hydrogen electrocatalysts.

Fischer–Tropsch synthesis, the conversion of CO and H2 to long-chain hydrocarbons, is performed at relatively low temperatures and high pressures over the most commonly encountered iron-, ruthenium...

Crystal structures and surface energies of transition metals are of fundamental importance to the activity, selectivity and stability in heterogeneous catalysis, but the interplay between crystal s...

Considerable attention has been drawn to tune the geometric and electronic structure of interfacial catalysts via modulating strong metal-support interactions (SMSI). Herein, we report the construction of a series of TiO

The effects of increasing blood flow on the pathogenic wall shear stress (pWSS) of subclavian arteries (SAs) are currently unclear. Patient-specific models of the SA were constructed based on computed tomographic images from two patients. Using the Ansys Fluent 19.0 transient laminar flow solver, the finite volume method was chosen to solve the Navier–Stokes equation governing fluid behavior. The time-averaged wall shear stress, ratio of risk area, cumulative ratio of risk area ([Formula: see text]), ratio of risk time, and ratio contour of risk time were calculated to describe the temporal and spatial distributions of pWSS. Virtually all pWSS occurred during the diastolic phase. The [Formula: see text]was 2.3 and 1.29 times higher on the left than on the right in Patients 1 (P1) and 2 (P2), respectively. Increasing the blood flow volume of the left SA by 20%, 40%, and 60% led to a 9.27%, 15.10%, and 20.99% decrease in[Formula: see text] for P1 and a 5.74%, 11.55%, and 17.14% decrease in [Formula: see text] for P2, respectively, compared with baseline values. In conclusion, the left SA showed greater diastolic pWSS than the right SA, and increasing the blood flow volume reduced the pWSS in the left SA.

CO methanation is an industrially important reaction for the removal of trace amounts of CO from the hydrogen feed for ammonia production and in proton exchange membrane fuel cells. Although the H-assisted CO dissociation mechanism has been extensively elucidated, discrepancies exist in determining through which C1-oxygenate intermediates the C–O bonds are broken. Using density functional theory calculations and microkinetic studies, we show that theoretical studies can reach agreement in C–O bond scission via the CHO intermediate on Co(0001) at a low coverage regime, and this mainly controls the CO methanation rate. This mechanism is independent of the functionals considered and the presence of graphitic carbon, and likely also pertains to other Co surface structures, including some open facets and step sites. The work provides fundamental insights into the mechanistic discrepancies relating to CO activation and methanation on hexagonal close-packed Co catalysts, which can potentially be used to design improved CO hydrogenation catalysts.

Gastric cancer (GC) is one of the leading causes of cancer-related deaths in our country. Circular RNAs (circRNAs) are being found to have relevance to human cancers, including GC. The purpose of this study was to investigate the functional role of circRNA BTG3 associated nuclear protein (circBANP) in GC and underlying mechanisms governing it. CircBANP was identified using RNase R assay and polymerase chain reaction (PCR) with specific primers. The levels of circBANP, let-7a and Frizzled-5 (FZD5) mRNA were assessed by quantitative real-time PCR (qRT-PCR). Cell proliferation, colony formation ability, apoptosis, and migration and invasion were determined by Cell Counting Kit-8 (CCK-8) assay, colony formation assay, flow cytometry, transwell assay, respectively. The targeted interaction between let-7a and circBANP or FZD5 was confirmed by dual-luciferase reporter assay or RNA pull-down assay. Western blot analysis was performed to detect the indicated protein expression. A xenograft model assay was established to observe the role of circBANP in vivo. We found that circBANP was up-regulated in GC tissues and cell lines, and associated with clinicopathologic features of GC patients. CircBANP knockdown repressed the proliferation, migration, invasion, and promoted the apoptosis in GC cells. CircBANP sequestered let-7a by acting as a molecular sponge of let-7a. Moreover, the regulatory effect of circBANP on GC cell progression in vitro was mediated by let-7a. CircBANP protected against FZD5 repression by sponging let-7a in GC cells. Wnt/β-catenin signaling was involved in the regulatory network of the circBANP/let-7a axis in GC cell progression. Additionally, circBANP depletion retarded tumor growth in vivo. In conclusion, our study suggested that the knockdown of circBANP suppressed GC cell progression in vitro and in vivo at least partially through sponging let-7a and regulating FZD5/Wnt/β-catenin signaling, providing a novel mechanism for understanding the pathogenesis of GC.

Purpose Long non-coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR) has been reported to dysregulate in many tumors. However, the mechanism of HOTAIR was rarely reported in GC. Methods The levels of HOTAIR, microRNA-618 (miR-618) and Krueppel-like factor 12 (KLF12) in GC tissues and cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The cell viability and apoptotic rate were assessed via cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. The migrating and invading abilities were tested by Transwell assay. The protein levels of KLF12, p-PI3K, PI3K, p-ATK and ATK were measured by Western blot assay. These interactions between miR-618 and HOTAIR or KLF12 were predicted by DIANA tools, and then, dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted to validate these interactions. Besides, the xenograft tumor experiment was performed to further verify the roles of HOTAIR in GC. Results The levels of HOTAIR and KLF12 were significantly upregulated and the level of miR-618 was strikingly downregulated in GC tissues and cells. miR-618 was verified as a direct target of HOTAIR or KLF12. HOTAIR silencing blocked GC progression and PI3K/ATK signaling pathway by sponging miR-618 and also restrained xenograft tumor growth in vivo. miR-618 inhibited GC progression and PI3K/ATK signaling pathway by targeting KLF12. Mechanistically, HOTAIR modulated KLF12 expression by sponging miR-618 in GC cells. Conclusion These data unraveled that HOTAIR promoted GC progression through PI3K/ATK signaling pathway via miR-618/KLF12 axis.

Nitrogen-doped graphene is a promising non-precious metal electrocatalyst for the oxygen reduction reaction (ORR). We report that distorted nitrogen-doped graphene layers encapsulating Fe3Co nanoparticles supported on carbon (Fe3Co@NG-C) display excellent activity toward ORR in alkaline media. Compared with a commercial Pt/C electrocatalyst at a loading of 80 μgPt/cm2 on a rotating disk electrode, the Fe3Co@NG-C exhibits an onset potential positively shifted by 50 mV at 0.1 mA/cm2 and a nearly identical half-wave potential. The Fe3Co@NG-C has minimal activity degradation during accelerated durability testing and superior tolerance to methanol than commercial Pt/C. Density functional theory calculations combined with poisoning experiments reveal that the high activity of the Fe3Co@NG-C mainly arises from strain in nitrogen-doped graphene induced by encapsulation of Fe3Co nanoparticles with exposed (1 1 0) planes, which promotes stabilization of the key OOH* intermediate involved in ORR. Our study shows the rational design of improved carbon-based electrocatalysts for ORR can be achieved by using strain engineering.

Cobalt carbide based catalyst shows a promising activity and selectivity in the direct conversion of syngas (a mixture of carbon monoxide and hydrogen molecules) toward oxygenates and lower olefin....

Electrocatalytic reduction is a promising approach to remediate nitrate (NO3–), one of the world’s most widespread water pollutants. In the present work, we elucidate activity and selectivity trend...

Non-oxidative direct methane conversion provides a potentially economic and environmental friendly route for the use of natural gas and shale gas, but this process suffers the disadvantages of low ...

Identification of the structure sensitivity of nitrogen molecule (N2) activation and ammonia synthesis on metal surfaces is important for the mechanistic understanding and rational design of more efficient catalysts. In the present work, density functional theory calculations together with microkinetic simulations were performed to study the influence of cobalt crystal structures including hexagonal close-packed (HCP) and face-centered cubic (FCC) on nitrogen molecule dissociation and ammonia synthesis. Molecular and dissociative adsorption energies of N2 as well as dissociation barriers are calculated for a total of ten cobalt surfaces. It is found that molecular adsorption energies on Co surfaces vary modestly on the order of 0.25 eV, whereas dissociative adsorption energies and the corresponding barriers vary considerably in magnitude by about 0.80 eV. First-principles microkinetic simulations show that HCP Co displays higher activity than FCC cobalt for nitrogen molecule dissociation and ammonia synth...

Understanding the intrinsic catalytic properties of perovskite materials can accelerate the development of highly active and abundant complex oxide catalysts. Here, we performed a first-principles density functional theory study combined with a microkinetics analysis to comprehensively investigate the influence of defects on catalytic CO oxidation of LaFeO 3 catalysts containing single atoms of Rh, Pd, and Pt. La defects and subsurface O vacancies considerably affect the local electronic structure of these single atoms adsorbed at the surface or replacing Fe in the surface of the perovskite. As a consequence, not only the stability of the introduced single atoms is enhanced but also the CO and O 2 adsorption energies are modified. This also affects the barriers for CO oxidation. Uniquely, we find that the presence of La defects results in a much higher CO oxidation rate for the doped perovskite surface. A linear correlation between the activation barrier for CO oxidation and the surface O vacancy formation energy for these models is identified. Additionally, the presence of subsurface O vacancies only slightly promotes CO oxidation on the LaFeO 3 surface with an adsorbed Rh atom. Our findings suggest that the introduction of La defects in LaFeO 3 -based environmental catalysts could be a promising strategy toward improved oxidation performance. The insights revealed herein guide the design of the perovskite-based three-way catalyst through compositional variation.

Strong metal-support interactions (SMSI) is an important concept in heterogeneous catalysis. Herein, we demonstrate that the Au-TiO

The complete mitogenome sequence of Chodsigoa hoffmanni was determined using long PCR. The genome was 17,138 bp in length and contained 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, one origin of L strand replication, and one control region. The overall base composition of the heavy strand is A (32.8%), C (24.4%), T (29.8%), and G (13.0%). The base compositions present clearly the A–T skew, which is most obviously in the control region and protein-coding genes. Mitochondrial genome analyses based on MP, ML, NJ, and Bayesian analyses yielded identical phylogenetic trees. Chodsigoa hoffmanni is the first species to have been reported on the mitochondrial genome in Chodsigoa genus. This study verifies the evolutionary status of C. hoffmanni in Soricidae at the molecular level. The mitochondrial genome would be a significant supplement for the C. hoffmanni genetic background.

The complete mitogenome sequence of the striped hamster was determined using long PCR. The genome was 16,282 bp in length and contained 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, one origin of L strand replication, and one control region. The overall base composition of the heavy strand is A (33.7%), C (22.8%), T (30.5%), and G (13.0%). The base compositions present clearly the A–T skew, which is most obviously in the control region and protein-coding genes. Mitochondrial genome analyses based on MP, ML, NJ, and Bayesian analyses yielded identical phylogenetic trees. Results of phylogenetic analysis showed that Cricetulus had close relationship with Meriones. This study verifies the evolutionary status of the striped hamster in Cricetulus at the molecular level. The mitochondrial genome would be a significant supplement for the striped hamster genetic background. Results of phylogenetic analysis showed that the striped hamster had close relationship with C. griseus in Cricetulus.

The complete mitogenome sequence of Crocidura tanakae was determined using long PCR. The genome was 16,969 bp in length and contained 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, 1 origin of L strand replication and 1 control region. The overall base composition of the heavy strand is A (32.5%), C (22.3%), T (31.9%), and G (13.3%). The base compositions present clearly the A–T skew, which is most obviously in the control region and protein-coding genes. Mitochondrial genome analyses based on MP, ML, NJ, and Bayesian analyses yielded identical phylogenetic trees. The five Crocidura species formed a monophyletic group with the high bootstrap value (100%) in all examinations. This study verifies the evolutionary status of C. tanakae in Soricidae at the molecular level. The mitochondrial genome would be a significant supplement for the C. tanakae genetic background.

Synthesis of atomically dispersed catalysts with high metal loading and thermal stability is challenging but particularly valuable for industrial application in heterogeneous catalysis. Here, we report a facile synthesis of a thermally stable atomically dispersed Ir/α-MoC catalyst with metal loading as high as 4 wt%, an unusually high value for carbide supported metal catalysts. The strong interaction between Ir and the α-MoC substrate enables high dispersion of Ir on the α-MoC surface, and modulates the electronic structure of the supported Ir species. Using quinoline hydrogenation as a model reaction, we demonstrate that this atomically dispersed Ir/α-MoC catalyst exhibits remarkable reactivity, selectivity and stability, for which the presence of high-density isolated Ir atoms is the key to achieving high metal-normalized activity and mass-specific activity. We also show that the water-promoted quinoline hydrogenation mechanism is preferred over the Ir/α-MoC, and contributes to high selectivity towards 1,2,3,4-tetrahydroquinoline. The present work demonstrates a new strategy in constructing a high-loading atomically dispersed catalyst for the hydrogenation reaction., Atomically dispersed Ir/α-MoC catalyst with high metal loading exhibits remarkable activity, selectivity and stability for quinoline hydrogenation reaction through water-promoted hydrogenation mechanism.

The complete mitogenome sequence of the striped hamster was determined using long PCR. The genome was 16,282 bp in length and contained 13 protein-coding genes, two ribosomal RNA genes, 22 transfer...

The complete mitogenome sequence of Chodsigoa hoffmanni was determined using long PCR. The genome was 17,138 bp in length and contained 13 protein-coding genes, two ribosomal RNA genes, 22 transfer...

The complete mitogenome sequence of Crocidura tanakae was determined using long PCR. The genome was 16,969 bp in length and contained 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA...

Developing advanced Fischer-Tropsch synthesis (FTS) technology to acquire fuel and valuable chemicals from non-petroleum sources more efficiently is one of the important tasks in heterogeneous catalysis and chemical engineering research. With the purpose of improving iron-based FTS catalyst, we explored the modification effect of boron on the χ-Fe5C2 catalyst by density functional theory (DFT) calculations. Boron atom adsorption on χ-Fe5C2 surfaces is considered to modulate the stability as well as the activity of CO activation on FTS process. Anti-coking can be observed when boron atom adsorbs on χ-Fe5C2 catalyst due to the competitive adsorption and repulsive interactions between carbon and boron atoms. More open and active planes, such as (311), (021), and (31 2 ) facets, can expose in the morphology of χ-Fe5C2 when boron atom adsorbs on χ-Fe5C2. It is found that co-adsorbed boron atoms have little effect on the barrier of CO direct dissociation in most cases, while there is also particular situation that CO is adsorbed and activated on boron with carbon termination. Our work shed light on the promoting effects of boron adsorption on CO activation, which can provide useful guide for the design of novel iron-based FTS catalysts.

Vacancies, typically exist in various types and morphologies on the surfaces of transition metal compound catalysts, have been shown to play an important role in many catalytic reactions. However, identifying the optimal type and morphology of vacancy and the key factors that control its performance remains a significant challenge. By density functional theory calculations and microkinetic modeling, we show that compared to various threefold S vacancy morphologies on the basal plane, the lower coordination number at the bridge S vacancy of Mo edge on MoS2 tunes the relative adsorption strength of key intermediates (such as O relative to OH). This not only increases CO2 hydrogenation rate by 7–11 orders of magnitude, but also leads to clearly distinct mechanism (associative & redox). The large destabilization of O and low H coverage on the Mo edge also hinder C-O scission and hydrogenation (give CH4 and CH3OH) relative to CO desorption, leading to almost 100% CO selectivity. The inexpensive MoS2 catalyst provides an alternative to the traditional noble metal catalysts for reverse water gas shift, and the coordination number of vacancy modulated catalytic performance illustrates a promising way to design transition metal compound catalysts for other important reactions of technological interest.

A simplified method is presented to fabricate polymer composite electrodes for electrocardiograph (ECG) measurements. The composite electrode was fabricated by loading a high content of carbon nanotubes (CNTs) and silver nanoparticles (Ag NPs) in polydimethylsiloxane (PDMS). The conductive polymer mixture was prepared by ultrasonically stirring and heat-stirring. Polymer electrodes were fabricated by the doctor blade technique. Two-dimensional electrodes were fabricated to evaluate the effect of thickness on signal quality. Three polymer electrodes were combined into the ECG electrode patch. The polymer electrodes were successfully applied in ECG measurements. Continuous measurements for 14 days indicated the polymer electrodes are suitable for long-term monitoring. Wearable electrodes were fabricated with a layer of gauze embedded by the CNT/Ag-PDMS mixtures. Conductive wires were sewed in the gauze as connectors for the measurement circuit. Three wearable electrodes were sewed into a vest as a measurement module. The ECG measurement results demonstrated that the wearable electrodes are qualified for such medical devices. The CNT-based polymer electrodes are flexible, washable, and suitable for long-term wear, possessing great promise in practical applications in wearable medical instruments.

Fischer-Tropsch synthesis (FTS) is an increasingly important approach for producing liquid fuels and chemicals via syngas—that is, synthesis gas, a mixture of carbon monoxide and hydrogen—generated from coal, natural gas, or biomass. In FTS, dispersed transition metal nanoparticles are used to catalyze the reactions underlying the formation of carbon-carbon bonds. Catalytic activity and selectivity are strongly correlated with the electronic and geometric structure of the nanoparticles, which depend on the particle size, morphology, and crystallographic phase of the nanoparticles. In this article, we review recent works dealing with the aspects of bulk and surface sensitivity of the FTS reaction. Understanding the different catalytic behavior in more detail as a function of these parameters may guide the design of more active, selective, and stable FTS catalysts.

Gastric cancer (GC) is one of the leading causes of cancer-related deaths in our country. Circular RNAs (circRNAs) are being found to have relevance to human cancers, including GC. The purpose of this study was to investigate the functional role of circRNA BTG3 associated nuclear protein (circBANP) in GC and underlying mechanisms governing it. CircBANP was identified using RNase R assay and polymerase chain reaction (PCR) with specific primers. The levels of circBANP, let-7a and Frizzled-5 (FZD5) mRNA were assessed by quantitative real-time PCR (qRT-PCR). Cell proliferation, colony formation ability, apoptosis, and migration and invasion were determined by Cell Counting Kit-8 (CCK-8) assay, colony formation assay, flow cytometry, transwell assay, respectively. The targeted interaction between let-7a and circBANP or FZD5 was confirmed by dual-luciferase reporter assay or RNA pull-down assay. Western blot analysis was performed to detect the indicated protein expression. A xenograft model assay was established to observe the role of circBANP

Wet chemical synthesis (WCS), especially under high temperatures, is one of the most frequently used strategies for nanostructured material construction, which has been used extensively in medical-, energy-, and environment-related applications. Although knowledge about the WCS process has been accumulated in the past two decades, the high temperature used in the process and multiphase nature of intermediates and products are key factors preventing the processes from rationalization. In this paper, by using multilevel in situ cells, we developed a strategy to monitor the reaction details of WCS processed in the solid, liquid, and gas phase simultaneously. This protocol has proven successful to reconstruct the WCS process of Fe5C2 nanoparticles (NPs) and unravel the complicated chemistry in the synthesis process.

Structure sensitivity on chain growth and selectivity in cobalt catalyzed Fischer–Tropsch synthesis (FTS) were studied by density functional theory (DFT) calculations. It is found that at a lower CO coverage, chain growth tends to proceed via a CO insertion mechanism on close-packed Co (0001) and stepped Co, with CH4 as the main product. However, a carbide mechanism is preferable on more open Co (101) accompanied with higher selectivity to C2 hydrocarbons than CH4. The origin is identified from the structure sensitive adsorption of the key intermediates, specifically the least “saturated” C/CH species, which exhibit a relatively strong dependence on the structure evolution. With increasing CO coverage, the CO insertion mechanism becomes more favorable, and both FTS activity and C2 hydrocarbon selectivity increase on Co (0001). This work highlights the intrinsic structure and coverage effects, achieving fundamental insight that can potentially be used to design and develop improved catalysts for FTS and other important reactions in syngas conversion.

Exploring the dependence of the structure–activity relationship of catalysts is important for improving the activity and selectivity in heterogeneous catalysis. Among other factors, the influence of the crystal phases, face-centered cubic (FCC) and hexagonal close-packed (HCP), of Ni catalysts on CO dissociation is studied by density functional theory (DFT). Surface energies of numerous FCC and HCP facets are calculated to construct the corresponding morphologies, and the exposed facets (six facets for FCC Ni and five facets for HCP Ni) are used to investigate the CO dissociation. For FCC Ni, (311) is the most active facet with the least barrier of 1.58 eV, followed by (100) and (211) with barriers of 1.63 and 1.75 eV, respectively. For HCP Ni, (1012) is the most active facet with the least barrier of 1.73 eV, followed by (1011) with a barrier of 1.86 eV. On both FCC and HCP Ni, CO dissociation shows a dramatic structural sensitivity irrespective of direct or H-assisted pathway. Compared to the direct d...

In this study, the concept of polymer electrodes integrated with a wireless electrocardiogram (ECG) system was described. Polymer electrodes for long-term ECG measurements were fabricated by loading high content of carbon nanotubes (CNTs) in polydimethylsiloxane. Silver nanoparticles (Ag NPs) were added to increase the flexibility of the polymer and the conductivity of the electrode. An ECG electrode patch was fabricated by integrating the electrodes with an adhesive polydimethylsiloxane (aPDMS) layer. Holes in the electrode filled with aPDMS can enable robust contact between the electrode and skin, reducing motion artifacts. A wireless ECG measurement system was developed and adapted to the polymer electrodes. The polymer electrodes combined with the measurement system were successfully applied in wireless, long-term recording of ECG signals. An eleven-day continuous test showed that the ECG signal did not degrade over time. The results of attach/detach tests demonstrated that the ECG signal was affected by motion artifacts after six attach/detach cycles. The electrodes produced are flexible and exhibit good ECG performance, and therefore can be used in wearable medical monitoring systems. The approach proposed in this study holds significant promise for commercial application in medical fields.

Composite electrodes are fabricated for long-term electrocardiogram (ECG) measurements. The electrode consists of a polydimethylsiloxane base, silver nanowire layer, and adhesive layer. The adhesive layer is fabricated by loading carbon nanotubes into adhesive polydimethylsiloxane. An electrode patch consisting of three composite electrodes and an adhesive polydimethylsiloxane layer is fabricated and combined with a wireless acquisition system to obtain ECG measurements. The composite electrode patch is self-adhesive and can conform to the skin, achieving robust contact between electrode and skin and thus decreasing motion artifacts. The composite electrodes combined with the measurement system are successfully used for wireless long-term recording of ECG signals. Continuous testing for 8 days shows that the ECG signal amplitude decreases slightly after wearing for 6 days and can be largely recovered by cleaning with ethanol. The composite electrodes are flexible and exhibit good ECG performance, and therefore can be used in wearable medical monitoring systems.