Search

Angiogenesis is a key physiological process that plays a key role in glioblastoma (GBM) progression and displays therapeutic resistance to antiangiogenic therapies. In this study, we aimed to identify whether vascular endothelial growth factor receptor 2(VEGFR2)monoclonal antibodies(mab)could inhibit tumorigenicity and the formation of vascular mimicry (VM) in GBM. The bioinformatic analysis from TCGA, CGGA, and TCPA databases and Immunohistochemistry (IHC) revealed that VEGFR2 is highly expressed in glioma tissues and results in a poor prognosis and is positively associated with VM markers (CD34 and PAS). The anti-VEGFR2 monoclonal antibodies(MSB0254)could inhibit the invasion, migration, and VM formation of U251 and primary glioma cells in vitro. In vivo, MSB0254 (m) could not only inhibit the growth of transplanted tumors of U251 and GL261 cells, but also significantly inhibit the expression of CD34, VEGFR2, Ki67, MMP2, MMP9 and reduce the expression of CD34/PAS and inhibit VM formation. The VEGFR2 monoclonal antibody could inhibit the angiogenesis and tumor growth of GBM by blocking the signaling pathway mediated by VEGFR2. It may become a new supplementary treatment for GBM.

Performing high-fidelity computational fluid dynamics (HF-CFD) to predict the flow and heat transfer state of the coolant in the reactor core is expensive, especially in scenarios that require extensive parameter search, such as uncertainty analysis and design optimization. This work investigated the performance of utilizing a multi-fidelity reduced-order model (MF-ROM) in PWR rod bundles simulation. Firstly, basis vectors and basis vector coefficients of high-fidelity and low-fidelity CFD results are extracted separately by the proper orthogonal decomposition (POD) approach. Secondly, a surrogate model is trained to map the relationship between the extracted coefficients from different fidelity results. In the prediction stage, the coefficients of the low-fidelity data under the new operating conditions are extracted by using the obtained POD basis vectors. Then, the trained surrogate model uses the low-fidelity coefficients to regress the high-fidelity coefficients. The predicted high-fidelity data is reconstructed from the product of extracted basis vectors and the regression coefficients. The effectiveness of the MF-ROM is evaluated on a flow and heat transfer problem in PWR fuel rod bundles. Two data-driven algorithms, the Kriging and artificial neural network (ANN), are trained as surrogate models for the MF-ROM to reconstruct the complex flow and heat transfer field downstream of the mixing vanes. The results show good agreements between the data reconstructed with the trained MF-ROM and the high-fidelity CFD simulation result, while the former only requires to taken the computational burden of low-fidelity simulation. The results also show that the performance of the ANN model is slightly better than the Kriging model when using a high number of POD basis vectors for regression. Moreover, the result presented in this paper demonstrates the suitability of the proposed MF-ROM for high-fidelity fixed value initialization to accelerate complex simulation.

In this paper, the coupling of fine-mesh computational fluid dynamics (CFD) thermal-hydraulics (TH) code and neutronics code is achieved using the Ansys Fluent User Defined Function (UDF) for code development, including parallel meshing mapping, data computation, and data transfer. Also, some CFD schemes are designed for mesh mapping and data transfer to guarantee physical conservation in the coupling computation. Because there is no rigorous research that gives robust guidance on the various CFD schemes that must be obtained before the fine-mesh coupling computation, this work presents a quantitative analysis of the CFD meshing and mapping schemes to improve the accuracy of the value and location of key physical prediction. Furthermore, the effect of the sub-pin scale coupling computation is also studied. It is observed that even the pin-resolved coupling computation can also create a large deviation in the maximum value and spatial locations, which also proves the significance of the research on mesh mapping and data transfer for CFD code in a coupling computation.

Glioblastoma (GBM) is the deadliest primary brain tumor that is highly resistant to current treatments. Polo-like kinase 1 (PLK1) and signal transducer and activator of transcription 3 (STAT3) are highly expressed in gliomas, especially GBM. Previous studies have shown reciprocal activation between PLK1 and STAT3 and that they regulate the same pools of MYC downstream. We have demonstrated that PLK1 and STAT3 levels are elevated in gliomas compared with those in normal brain tissues, and high expression of both PLK1 and STAT3 is associated with poor prognosis in TCGA. Moreover, there was direct or indirect reciprocal regulation between PLK1 and STAT3. Furthermore, we found that PLK1 and STAT3 can regulate the same pools of MYC downstream. Compared to monotherapy, combined treatment of glioma cells with PLK1 and STAT3 inhibitors, BI2536 and Stattic, respectively, showed lower expression of MYC, synergistic induction of cell invasion and apoptosis in vitro, and tumor inhibition in xenografts. PLK1 and STAT3 were able to directly regulate the expression of MYC and induce apoptosis of glioma cells through the regulation of MYC. These findings may help develop a therapeutic strategy for dual inhibition of PLK1 and STAT3 against the tumorigenesis of glioma.

Aim To investigate the impact of circumferential tumour location on neoadjuvant chemoradiotherapy (CRT) response and its prognostic value for locally advanced rectal cancer (LARC) patients after CRT and surgery. Methods A retrospective study was performed on 486 patients with LARC who received neoadjuvant CRT and surgical treatment. The rate of pathological complete response (pCR) and survival among patients with anteriorly, laterally, and posteriorly located tumours were compared. Logistic regression was performed to identify pCR predictors. Results The anterior tumours exhibited the highest pCR rate of 26.7%, which was slightly higher than the 20.0% and 12.3% for lateral and posterior tumours, respectively (P = 0.006). The 5-year Overall survival (OS) rates after CRT were similar among the anterior, lateral, and posterior groups (anterior vs lateral vs posterior: 81.1% vs 89.9% vs 84.1%, P = 0.6368). Multivariate analysis revealed that the circumferential tumour location, post-CRT serum CEA and post-CRT tumour thickness measured by MRI were independently correlated with achieving pCR. Conclusion This study is the first, to the best of our knowledge, to show that anterior LARC exhibited the highest pCR rate after neoadjuvant CRT. Patients with anterior rectal cancers do not have different prognoses from those with non-anterior cancers if they undergo neoadjuvant CRT.

Glioblastoma (GBM) is a very frequent primary tumour in the cerebrospinal nervous system. Temozolomide (TMZ) is the first-line treatment for patients with GBM. However, some of GBM patients do not respond to TMZ. O6-methylguanine-DNA-methytransferase (MGMT) remains a major cause. In a previous study, we detected antibodies against MGMT peptides in patients with glioma, and five highly responsive autoantibodies anti-MGMT-02, anti-MGMT-04, anti-MGMT-07, anti-MGMT-10, and anti-MGMT-18 were identified that could be used to dynamically assess chemotherapy-resistant TMZ. Therefore, targeting MGMT peptides may be a potential therapeutic approach for GBM to fight TMZ resistance.First, MGMT-02 and MGMT-04 polypeptides with cell-penetrating peptides were designed and connected to FITC tracer for immunofluorescence localisation. CCK-8 and colony formation assay were performed to evaluate cell proliferation ability. Western blot and immunofluorescence analysis were used to detected the expression of apoptosis-related protein. Flow cytometry was used to detect the proportion of apoptosis in cells. TMZ-resistant effect of MGMT-02/04 peptides was assessed in intracranial xenograft nude mouse model.We also found reduced apoptosis of cells treated with MGMT-02 and MGMT-04 peptides and TMZ compared with those treated separately with TMZThe results of this study indicate that MGMT-02 and MGMT-04 peptides have a role in glioma resistance and that MGMT peptides may serve as a precise target for TMZ-resistant GBM.

Transition metal hydroxides play an important role in the development of high-efficiency electrocatalysts for water splitting. Here we report an advanced electrocatalyst made of NiCo layered double hydroxide (NiCo LDH) supported by three-dimensional (3D) NiCo foam (NCF). The microstructure and physicochemical properties of the NiCo LDH are custom-modified by the N2/Ar radio-frequency (RF) plasma. The plasma enables effective doping of the NiCo LDH catalyst with nitrogen (partial nitridization), leading to the substantial improvement of electrocatalytic performance of the N-doped NiCo LDH (N-NiCo LDH) for overall water splitting in 1 M KOH. The overpotentials required to transfer a current density of 10 mA cm−2 (η10) in the HER and OER processes are 100 mV and 190 mV, respectively. At this current density, the H2 and O2 amounts generated by the N-NiCo LDH catalyst in 1 M KOH electrolyte are about 90 and 48 μmol h-1, respectively. The demonstrated electrocatalytic performance is very competitive with other state-of-the-art catalysts based on similar layered double hydroxide materials systems.

In situ engineering highly active and ultrastable bi-functional electrocatalysts based on metal ions from transition metal alloys that are simultaneously suitable for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is one of the key unresolved challenges on the way to energy-efficient hydrogen fuel production by water splitting. One such novel catalyst based on polyhedron N-doped Ni-Co phosphide is burgeoned directly from the Ni-Co foam (N-NiCoP/NCF) using a facile and eco-friendly approach without involving heavy metal ions. The N-NiCoP/NCF catalyst exhibits superior activity in 1.0 M KOH for overall water splitting, evidenced by the low overpotentials of 78 mV for HER and 225 mV for OER at a current density of 10 mA cm-2. The excellent electrocatalytic activity of N-NiCoP is attributed to the increased Fermi level due to effective N-doping and the abundant exposed active crystal planes (311) of heterostructured Co2NiP4 phase. Importantly, the N-NiCoP/NCF catalyst shows ultra-stable electrocatalytic performance while retaining structural integrity in both HER and OER processes during continuous reactions for over 100 h. These results open new avenues for in situ engineering of transition-metal based electrocatalysts used for renewable energy generation.

Hydrogen, generated by electrocatalytic process, is one of the most promising sources of green and sustainable energy. Herein, we report a novel elctrocatalyst for hydrogen evolution reaction (HER) fabricated by doping Ni foam (NF) supported Ni2P nanosheets with Cu atoms. The Cu atoms effectively tune the structure and physicochemical properties of Ni2P, leading to the lower HER free energy, improved electrical conductivity, and high exposure of surface active sites. The optimized Ni1.8Cu0.2-P displays an excellent catalytic performance and stability, which is demonstrated by the low overpotentials of 78 (Tafel slope: 70 mV dec-1) and 245 mV to reach a current density of 10 and 100 mA cm-2 for the HER in 1.0 M KOH. The high electrocatalytic activity of Ni1.8Cu0.2-P is attributed to the increased Fermi level and the exposed active crystal plane (201). The H2 amount produced with a current density of 10 mA cm-2 is about 1.91 mmol h-1 cm-2, which is the highest value among the reported non-precious metal catalysts.

The use of aerogels to selectively recover oil from oily wastewater is effective but challenging. In this study, a new carboxylated carbon nanotube/chitosan aerogel (CCNT/CA) with switchable wettability was developed as a smart adsorbent for fast oil absorption and oil recovery. Vinyltrimethoxysilane and thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm) was grafted onto the surface of the CCNT/CA skeleton, and the resulting smart aerogel (PNI-Si@CCNT/CA) exhibited temperature responsiveness. PNI-Si@CCNT/CA exhibited an excellent reversible conversion between hydrophilicity and hydrophobicity when the temperature was changed to below or above the lower critical solution temperature (LCST) of PNIPAAm (~32 °C). Most importantly, CCNT significantly increased the oil absorption capacity, improved the mechanical properties, accelerated phonon conduction, enhanced thermal conductivity (80.57 mW m

In this research, we compared the discharge characteristics and catalytic efficiency of sulfuric acid, p-toluenesulfonic acid, and their respective sodium salts (sodium sulfate and sodium p-toluenesulfonate) in sawdust liquefaction and found that sulfuric acid was the optimal catalyst when glycerol was used as solvent during the plasma electrolytic liquefaction (PEL) process. When sodium p-toluenesulfonate was used as the only catalyst, the liquefaction yield reached 83.51% after 25 min. This yield was higher than that obtained using sodium sulfate as the catalyst (60.63%) because different concentrations of H ions were produced in PEL. Cellulose, lignin, and holocellulose were extracted from sawdust and successfully liquefied in PEL, illustrating the universality of PEL. The optical emission spectra of the different biomass during the PEL process were similar, indicating that the kinds of free radicals produced were similar, which can accelerate the liquefaction of sawdust.

Developing bifunctional electrocatalysts of high-efficiency and new structures for overall water splitting are highly desirable and ongoing challenge. Herein, CoxNi10-x layer double hydroxide salts with controllable structure and morphology induced by 2-methylimidazole to derive ZIF-67 on Ni/Fe foam is reported. The as-prepared 3D CoxNi10-x layer double hydroxide microspheres are constructed by self-assembly of 2D nanoflake and 1D nanorod with ZIF-67 particles due to the double influence of Ni and 2-methylimidazole. It is discovered that the Ni and 2-methylimidazole can simultaneously modulate morphology and structure of CoxNi10-x layer double hydroxide to distinctly increase the electrochemical active surface area for exposing more accessible active sites. Notably, the 3D microsphere heterogeneous catalysis of the self-assembly combines the merits of low dimensions (1D and 2D) materials, providing high structural void porosity and fast charge transport channels. Particularly, the Co7Ni3 layer double hydroxide salts@ZIF-67/Ni/Fe foam exhibits the highest electrocatalytic activity with the lower overpotentials of 260 and 165 mV toward oxygen evolution reaction and hydrogen evolution reaction at current density of 10 mA cm−2, respectively. The outstanding activity originates from the strong electronic coupling between the 3D microsphere and ZIF-67. This work can bring a new prospect for fabricating highly-active and new structure electrocatalysts.

A facile and effective approach for fabricating a 3D nanostructured catalyst based on nonprecious metals for water splitting is reported. The Ni-Fe foam (NFF) is pretreated by a dielectric barrier discharge (DBD) plasma under ambient conditions, resulting in numerous microtrenches on the NFF surface. Meanwhile, some NiO and Fe2O3 spots appear on the NFF foam upon exposure to hot filaments generated in DBD plasmas in air. Cross-linked 3D CoS/Ni3S2-FeS nanopetals emerge on plasma treated NFF surface (PNFF) through sulfurization of Co nanosheets electrodeposited on PNFF. The produced CoS/Ni3S2-FeS/PNFF nanocomposite exhibited high electrocatalytic activity and stability for the overall water splitting. Benefiting from the 3D hierarchical nanoarchitecture of CoS/Ni3S2-FeS/PNFF with a large surface area, fast electron transport, and low free energy for adsorption, a current density of 10 mA cm−2 is achieved for the HER and OER with ultralow overpotentials of 75 mV and 136 mV, respectively. The amounts of H2 and O2 produced at a normalized current density of 10 mA cm−2 in 1 M KOH are about 680 μmol h−1 and 1230 μmol h−1, respectively. These values are very competitive compared with the state-of-the-art results reported for noble metal-free electrodes in alkaline media.

The conventional deterministic safety margin lacks the capability for real safety margin estimation in nuclear power plants (NPPs). To improve the accuracy of safety margin analysis, the risk-informed safety margin characterization (RISMC) approach has been proposed to capture the real safety margin in NPPs. However, existing literature lacks detailed application of the RISMC approach to improving the efficiency of safety margin analysis. To solve this problem, an advanced probability safety margin (APSM) analysis approach is proposed to improve safety margin analysis efficiency. The proposed APSM combines, the best estimate plus uncertainty (BEPU) analysis approach and the probability safety assessment (PSA) approach to screen key sequences. To reduce the number of calculation samples of Monte Carlo approach, the small sample estimation method is used to obtain the conditional exceedance probability (CEP). The proposed approach is subsequently used to estimate the reactor core damage frequency (CDF) of a 900 MW pressurized water reactor (PWR) under a small break lack of coolant accident, and for two reactor power levels. Evaluation results show that the proposed APSM analysis approach efficiently and accurately quantifies the core damage frequency under different reactor statuses. Moreover, the total number of calculation sequences is reduced from 64 to 8 and the total number of iterations is reduced from 8,320 to 520. In addition, the proposed APSM approach is compared with the PSA-only approach under 105% power condition. The comparison result shows that, the CDF obtained by APSM is 41% lower than that of the PSA. Moreover, for the APSM, the core damage frequency increased by 152.98% with core power uprates at 5%.

A vortex street structure in a narrow channel can not only enhance the mixing efficiency of the turbulence, but also cause flow-induced vibration. In this study, a rectangular channel with a single cylinder was used as the research object. The generation and influence factors of the turbulent vortex street structure in the channel and the flow-induced vibration of a cylindrical structure caused by the vortex street structure were numerically studied. First, based on the experimental data and numerical results, the accuracy of the numerical method used in this study for the flow field calculation and fluid–structure coupling calculation was verified. Second, the influence of the rod–wall gap size (W/D) on the vortex street structure formation and turbulent mixing efficiency was studied based on the validated numerical method. Finally, the flow-induced vibration of a cylindrical structure caused by a vortex street structure in a narrow channel was numerically studied using a weak coupling algorithm, and the influence of W/D on the vibration characteristics of the cylindrical structure was obtained. The results showed that an RSM-e anisotropic turbulence model could accurately capture the vortex street in a narrow channel. The value of W/D had a significant effect on the formation of the vortex street structure. When W/D is greater than 1.150, the vortex street structure disappears. The presence of vortex street structure can significantly enhance the mixing efficiency of turbulent flow. The vortex street structure also caused the buckling of the cylinder in the normal direction of the narrow channel.

Ethnopharmacological relevance Rhubarb is a natural herbal medicine widely used clinically with numerous pharmacological activities including anti-cancer. Specifically, several studies reported that free anthraquinones from Rhubarb suppressed the proliferation of hepatoma cells. Nonetheless, recent studies revealed that Rhubarb caused hepatotoxicity in vivo, confirming its “two-way” effect on the liver. Therefore, the efficacy and safety of Rhubarb in the in vivo treatment of liver cancer should be further elucidated. Aim of the study: This study investigated the presence of hepatoprotection or hepatotoxicity of Rhubarb in diethylnitrosamine (DEN)-induced hepatocarcinogenesis. Material and methods A total of 112 male Sprague-Dawley rats weighing 190–250 g were enrolled. The rats were induced hepatocarcinogenesis using diethylnitrosamine (0.002 g/rat) until 17 weeks. Starting at week 11, Rhubarb granules (4 g/kg and 8 g/kg) were intragastrically administered daily for 7 weeks. All rats were euthanized at week 20 and the livers were analyzed via non-targeted metabolomics analysis. We established hepatic glucose 6 phosphate (6PG) levels and glucose 6 phosphate dehydrogenase (G6PD) activities to assess the pentose phosphate pathway (PPP). And the liver injuries of rats were analyzed via histological changes, hepatic function, as well as hepatic protein levels of alpha-fetoprotein (AFP), pyruvate kinase isozyme type M2 (PKM2), and proliferating cell nuclear antigen (PCNA). Furthermore, polydatin (0.1 g/kg/d) as a specific inhibitor of G6PD was used to treat rats. Notably, their histological changes, hepatic function, hepatic 6PG levels, hepatic G6PD activities, PCNA levels, and PKM2 levels were recorded. Results Non-targeted metabolomics revealed that Rhubarb regulated the PPP in the liver of Rhubarb-DEN-treated rats. Besides, Rhubarb activated the oxidative branch of the PPP by activating G6PD (a rate-limiting enzyme in the oxidative PPP) in the liver of Rhubarb-DEN-treated rats. Meanwhile, Rhubarb promoted DEN-induced hepatocarcinogenesis. Moreover, polydatin attenuated the promoting effect of Rhubarb on DEN-induced hepatocarcinogenesis. Conclusions Rhubarb promoted DEN-induced hepatocarcinogenesis by activating the PPP, indicating that the efficacy and safety of Rhubarb in the treatment of liver cancer deserve to be deliberated.

The major challenges related to non-noble-metal electrocatalysts toward the hydrogen evolution reaction (HER) in an acidic environment are to overcome their low efficiency and poor stability. For this purpose, we propose a rational top-down method to construct a hybrid structure of nickel encased by a carbon shell (Ni@C) using CH4 as a carbon source and Ni wire as a sacrificing template during an electrical explosion of wire. The Ni@C nanoparticles are introduced as highly active and durable non-noble metal electrocatalysts for the HER. The optimized Ni@C (15%) core-shell catalyst (CH4/Ar = 15/85 pressure ratio) demonstrates the highest catalytic activity for the HER with an overpotential of 85 mV to drive a current density of -10 mA cm−2 and displays a low Tafel slope of 44 mV dec−1. Another virtue of Ni@C (15%) is its superior stability during an unattenuated HER chronoamperometry for over 24 h. Furthermore, it endures over 168 h submerging in 2 M H2SO4 solution without losing its catalytic activity for HER.

The plasma modification of the polypropylene (PP) membrane as a separator in lithium-ion battery (LIB) has been reported in this paper. Specifically, a commercial PP separator was modified by an atmospheric pressure glow discharge plasma jet (APGD-PJ) with the acrylic acid (AA) monomer. The morphology, electrolyte uptake and retention, the pore size distribution, and the electrochemical properties of the modified PP separator were analyzed. The experimental results indicate that the AA polymer (PAA) was uniformly coated on the surface of the PP membrane, and the contact angle of modified PP was reduced from 112° to 39° using He/O2/AA plasma and the electrolyte uptake of the modified PP separator increased to above 300% of the value of the unmodified one. Compared with the original PP, the cells assembled with the PP separator modified with Ar/O2/AA or He/O2/AA plasma showed higher capacities and better C-rate capacity. The excellent performances of assembled LIB endow the APDG-PJ as a promising protocol for modifying polyolefin separators for LIB applications.

In the traditional desorption method, strong acid is commonly used as an eluent for the regeneration of adsorbents. It is of critical economic and environmental significance to develop a chemical-free desorption method. In this study, a new CO2-responsive chitosan aerogel adsorbent was synthesized from CO2-responsive poly(acrylic acid-2-(dimethylamino)ethyl methacrylate) and chitosan by physicochemical double crosslinking for the adsorption of Cu2+. Compared with the chitosan aerogel, the adsorption capacity of Cu2+ and mechanical properties of CO2-responsive chitosan aerogel increased by 162% and 660%, respectively. Most importantly, after the adsorption of Cu2+ by CO2-responsive chitosan aerogel, the Cu2+ could be desorbed by CO2 bubbling, and the desorption rate of metal ions was more than 80%. The adsorption of Cu2+ by aerogel was attributed to chelation and complexation. The desorption of porous chitosan/P(AA-co-DMAEMA) aerogels (CPA) by CO2 mainly occurred through charge repulsion of protonated ‒NH2 and ‒N‒ groups. After 6 cycles, the adsorption capacity of CPA for metal ions still reached 70% of the initial adsorption capacity, and the desorption rate reached 75%. This novel CO2-responsive chitosan aerogel is a highly efficient and environmentally friendly adsorbent for the adsorption and recovery of metal ions.

Without efficiency, the CFD simulation of a reactor will not be affordable. However, numerous narrow flow channels with thousands of complex spacer grid exist in a typical pressurized water reactor (PWR) core. The huge burden in both computational resources and time is a key challenge. To realize a reduction of the computational burden, research on flow characteristics affected by RANS models and typical structures of PWR have been done. Based on the flow characteristics, a CFD scheme was designed by a hybrid application of multiple RANS models (MRANS). Different from the traditional turbulence scheme which just use one single RANS model, MRANS keeps the isotropic RANS models used in the major domains, and the anisotropic RANS modes used in the small local domains. After some validations, it was found that MRANS can successfully keep the accuracy and improve the computing efficiency by nearly two times. This superiority in efficiency could play an important role in the CFD simulation for a whole PWR.

The Pressurized Water Reactor (PWR) has numerous complex and narrow structures, such as a spacer grid, mixing vane, and narrow channels. Experiments can be used to research the flow characteristics in a reactor. However, using some simplification and approximation cannot be avoided: for example only several fuel rods are used and some solid walls are imposed for modeling the flow in a reactor core. The influence of these simplifications needs to be considered and discussed clearly, since the influence certainly exists and it may result in errors. To obtain a good understanding, this research has studied the impact created by the experimental conditions. The regularities found in this research can be used as a guide for the optimal design and utilization of an experiment to study the physical processes in a PWR.

Chemical waste-free, in situ synthesis of customized earth-abundant-metal based catalysts for high-efficiency water splitting still remains a formidable challenge. Here, Ni-Co hydroxide nanosheets (NCHS) are sprouted from Ni-Co foam (NCF) using an eco-friendly, pure-water-based method, and then are phosphorized and nitrided in N2 + P plasmas. The resulting N-doped Ni-Co phosphide catalyst (N-NiCoPx/NCF) exhibits excellent electrocatalytic performance, heralded by the low overpotentials of N-NiCoPx/NCF for generating a current density of 10 and 400 mA cm−2 (j10 and j400) in 1 M KOH of only 23 and 191 mV for the hydrogen evolution reaction (HER), and 298 and 410 mV for oxygen evolution reaction (OER), as well as by the low decay of high current density (j100) in the HER (6.02%) and OER (3.07%) processes for 100 h. Ab inito numerical simulations confirm that Co atom bonded with N represents the active center for overall water splitting.

Transition metal selenides are highly promising for clean hydrogen energy generation by overall water electrolysis. Here we report a new approach wherein highly efficient and ultra-stable bifunctional electrocatalyst is developed by synergistic atmospheric-pressure plasma, hydrothermal and selenization treatments of bimetallic electrodes leading to multiphase Ni-Fe-selenide nanosheets (MNFSNs). The remarkable performance in water splitting is evidenced by the low overpotentials for delivering a current density of 10 and 300 mA cm−2 (j10 and j300), which are only 56 and 288 mV for HER, and 200 and 342 mV for OER, respectively, along with robust durability. Moreover, the current densities 10 and 100 mA cm-2 are achieved at low cell voltages of 1.46 and 1.60 V, thus outperforming most of the reported electrocatalysts in two-electrode alkaline water electrolyzers. Ab initio atomistic simulations identify the active catalytic sites formed by Ni atoms located at the heterointerfaces between the FeSe2 and NiSe2 phases.

Prediction and analysis of coolant flow and mixing problems in the reactor pressure vessel (RPV) are some of the most critical studies to ensure system safety and balance of nuclear power plant. The flow mixing problem in the reactor primary system with complicated interior structure is a large domain three-dimensional problem. In this paper, we investigated the performance of utilizing multiple RANS models (MRANS) coupling method in the computational fluid dynamics (CFD) code ANSYS FLUENT to study flow mixing. Based on the domain decomposition technique, the 2-equation and 7-equation RANS models were coupled and applied to simulate the flow mixing phenomenon in the Rossendorf Coolant Mixing Model (ROCOM) test facility. First, a CFD model of ROCOM was developed, and the explicit domain decomposition coupling simulation was achieved with a user-defined Python control program. To ensure the best CFD model was utilized, three different turbulence models and varying resolution grids were used for turbulence model feasibility analysis and grid sensitivity testing. Then the applicability of MRANS coupling method was evaluated by comparing the results from the MRANS simulations with those obtained from flow mixing experiments. In addition, single and MRANS model simulation results were compared. Results show good agreements between the MRANS coupling simulations and the experimental data. Compared with overall simulations by single RANS models, the MRANS coupling method also have superior performance in accuracy and efficiency for the CFD simulation study of mixing phenomena in the reactor primary coolant system.

Bi-functional electrocatalysts capable to simultaneously sustain hydrogen and oxygen evolution reactions (HER, OER) under industry-relevant conditions of hydrogen production by water electrolysis are highly desired. Here, we implement a new concept of plasma-enabled simultaneous N-P heteroatom doping to achieve the highly-competitive activity and stability of trimetallic Ni-V-Fe bi-functional electrocatalysts on a NiFe foam (N-NiVFeP/NFF), evidenced by the lower overpotentials for HER (79 mV) and OER (229 mV) to deliver a current density of 10 mA cm−2 (j10) in the 1.0 M KOH electrolyte. Meanwhile, the N-NiVFeP/NFF exhibits ultra-stable performances with a current density from 10 to 100 mA cm-2 for over 100 h. Specifically, the HER and OER performances are near to those of noble-metal based electrocatalysts in the high current density region (> j200), attributing to the rich active sites exposed on the formed heterointerfaces among Ni-V-Fe phospho-nitrides, the changed electronic structure, and increased conductivity with nitrogen doping.

In-situ engineering multiple-phase transition-metal based electrocatalyst with excellent performances for hydrogen evolution reaction (HER) is still a major challenge in the electrocatalysis field. Herein, the Mo–Ni–Co trimetallic selenide nanorod arrays are synthesized on a plasma-treated Ni–Co foam (MoSe2–NiSe2–CoSe2/PNCF). The synergistic effects of heterostructured crystal interfaces, the formed 1T-2H mixture phases of MoSe2, and the customized morphological design enable high electrocatalytic activity and stability for the hydrogen evolution reaction (HER) in alkaline media. The catalysts require a low overpotential of 38 mV, just above commercial Pt/C electrodes (35 mV), to deliver a benchmark current density of 10 mA cm−2 (j10). The H2 generation amount (2.6 mmol h−1) is much higher than most of the reported transition-metal based electrocatalysts. Numerical simulations attribute the high electrocatalytic activity to the increased Fermi level with multiple heterointerfaces. The catalyst presents a superior long-term electrochemical stability during continuous reactions with a high current density (j100) for over 100 h. The success of enhancing the electrocatalytic performance paves new avenues for in situ engineering transition-metal based electrocatalysts for energy-related applications.

Water electrolysis using non-precious transition metal-based electrocatalysts is one of the most promising ways for renewable hydrogen energy. Herein, we develop high-performance catalysts of trimetallic sulfide (Ni3S2-FeS-CoS) nanosheets decorated with bimetallic-nitroxide (NiCo(N,O)x) nanodots on a 3D NiFeCo foam by in situ fabrication with approaches of the dielectric barrier discharge (DBD) plasma and hydrothermal sulphurization. The resulting catalyst shows excellent electrocatalytic activity for overall water splitting in alkaline medium, with the overpotentials 82 m V for hydrogen evolution reaction (HER) and 170 m V for oxygen evolution reaction (OER) at a current density of 10 mA cm−2 (j10), which are very competitive to most recent non-noble-metal electrocatalysts. Specially, the nanodots help achieve ultra-stable electrocatalytic performance evidenced by negligible changes for the physico-chemical structure of catalyst after a harsh HER or OER test over 50 h. Our results offer a versatile approach for the development of next-generation electrocatalysts for hydrogen economy and other applications.

This paper reports the synthesis of nanosized Ag/Co3O4 composite catalysts using a silver-mirror reaction and the calibration of their catalytic activities towards methyl blue (MB) dye degradation with peroxymonosulfate (PMS) under visible light. The nanosized Ag/Co3O4 composites were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV–vis spectroscopy. The experimental evidence indicated that the hydrothermal synthesis approach lead to the exposure of the {1 1 2} facets of the Co3O4 nanoflakes. Compared to Co3O4 nanoflakes, Co3O4 doped with Ag nanoparticle (average diameters of 10–15 nm) presented lower band gap energy and photoluminescent (PL) intensity. Meanwhile, the Ag/Co3O4 exhibited high stability and excellent dispersion property in dye solution. Experimental data suggested that 3.06 wt% Ag nanoparticle-doped Ag/Co3O4 nanocomposite catalyst possessed the highest catalytic activity towards MB degradation in aqueous solution at the tested concentration level of 15 mg/L, about 2.4 times higher than that of pure Co3O4. Complete decolorization of the 15 mg/L MB solution can be achieved by 3.06 wt% Ag-doped Ag/Co3O4 nanocomposite within 20 min of visible light irradiation.

PH-797804 is a selective p38 MAPK inhibitor currently evaluated in clinical trials. This study described a validated UPLC-MS/MS combined with one-step protein precipitation extraction method for determination of PH-797804 in rat plasma. After protein precipitation with acetonitrile, the plasma sample was analyzed by a Waters Acquity UPLC BEH C18 column, with acetonitrile/0.1% formic acid (70:30) as the mobile phase. Mass spectrometric detection was conducted with a Waters TQ-S mass spectrometer via electrospray, positive-mode ionization, with target quantitative ion pairs of m/z 476.895 → 126.860 for PH-797804, and 482.726 → 269.707 for regorafenib (internal standard). The assay showed a good linearity over the range of 1.0–1600 ng/mL, with acceptable accuracy (RE from −7.8% to 8.5%) and precision (RSD within 8.4%) values. Recovery from plasma was 81.4–90.2% and matrix effect was negligible (93.3–95.4%). The validated method presented a quantification method of PH-797804 in detail for the first time and utilized for a pharmacokinetic study at three dose concentrations after oral administration in Wistar rats. The pharmacokinetic profiles of PH-797804 showed a linear relationship between drug concentration and dose, which provided dosage and safety information on further clinical studies.

In this study, we deposited nano-Co3O4 film on silicon substrate using plasma-enhanced metal—organic chemical vapor deposition (PEMOCVD), and the structure difference of Co3O4 crystallized by the annealing and the Ar/O2 plasma techniques were explored by SEM, TEM, XRD, and XPS. Compared to the net morphology of Co3O4 film treated with high calcinations temperature, the cauliflowers-shaped micro-clusters were changed to nano-catkin when the sample was treated with Ar and O2 plasma for 40 min. Additionally, both samples (annealed and plasma-treated) showed the formation of both the {311} and {220} planes. The surface richness of active Co3+ sites on the exposed {220} plane indicated that the as-deposited nano-Co3O4 films have potential catalytic properties for CO and hydrocarbon oxidation.

In this paper, a two-step process was explored for the modification of poly(ethylene terephthalate) (PET) fabrics by Ar/O 2 plasma-induced polymerization with hexamethylene diamine (HMD) monomer. The first step involved a parallel-plate shape dielectric barrier discharge (DBD) apparatus to modify the PET fabrics. This treatment could introduce some polar groups onto the PET surface, and also simultaneously increased the surface roughness. Thus, this process was very helpful to increase the linking intensity between the fabric substrate and the later polymerized layer. For the second step of the process, an atmospheric pressure plasma jet (APPJ) apparatus with Ar and O 2 as working gases was employed to achieve the polymerization with HMD monomer on the fabric surface. The measurement of the plasma gas temperature by infrared thermometry, and the detection of reactive species by optical emission spectroscopy were used for characterizing the polymerization process. It was found that the plasma gas temperature was not higher than 307 K when the applied power was lower than 50 W, and many reactive species (e.g. •OH, •H, •O) existed in the plasma. Field emission scanning electron microscopy images showed that the surface roughness of PET increased greatly with the DBD plasma treatment, and a smooth thin film was formed under the APPJ polymerization with HMD monomer. Fourier transform infrared spectroscopy results indicated that HMD polymer was incorporated into PET fabrics through the formation of new covalent bonds. Chemical composition was analyzed by X-ray photoelectron spectroscopy, and many functional groups (e.g. C–N, O = C–NH) occurred on the PET fabric surface. Meanwhile, the dyeing property of modified PET evaluated by color yield (K/S) analysis was improved obviously.

The biofilm of allylamine polymer was deposited by using the liquid sputtering apparatus, which was achieved by the atmospheric: cold plasma plume. The surface roughness of the polymer was improved by increasing the power and He gas velocity. The average allylamine polymer deposition rate was about 30 nm/min. Rich morphologies (e.g., nanoline, microcloudlet) appearing on the biofilm revealed the important information of the growing processes that occurred in the plasma deposition. The density of the amine groups was obviously related to the plasma parameters, and the highest density of amino-labeled DNA probe was about 0.9 pM/cm(2) confirmed by the dyed oligonucleotide. (C) 2008 Elsevier B.V. All rights reserved.

Using hexamethyldisiloxane (HMDSO) monomer, the magnetic nanoparticles (NPs) of nickel oxide (NiO) were modified by using an atmospheric room-temperature plasma fluidized bed (ARPFB). The plasma gas temperature of the ARPFB was not higher than 325 K, which was favorable for organic polymerization. The plasma optical emission spectrum (OES) of the gas mixture consisting of argon (Ar) and HMDSO was recorded by a UV–visible monochromator. The as-treated NPs were characterized by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The results show that the assembling NPs were isolated greatly after modified by the organosilicon polymer. Moreover, this treatment process changed the wettability of the NPs from super-hydrophilicity to super-hydrophobicity, and the contact angle (CA) of water on the modified NPs surface exceeded 150°. Therefore, the ARPFB is a prospective technology for the NPs surface modification according to the different requirements.

Plasma electrolytic oxidation (PEO), also called micro-arc oxidation (MAO) or anode spark deposition (ASD), is a novel technique to produce hard ceramic coatings on metals, such as aluminum, titanium, magnesium (called valve metals) and their alloys. Up to now, many researchers focused on the PEO process for workpieces of regular shapes such as cube, cake or stick samples, etc. But no one paid attention to the irregular samples such as tubular materials. This research emphasized the PEO process of long tubes, especially the way to obtain uniform thickness of ceramic coatings on inner surface of tubes. Furthermore, the PEO kinetic behaviors of aluminum tubes were also investigated. The potential difference between the electrodes indicated a linear relationship with the coating thickness. A central accessory electrode was axially used to eliminate the shielding effect of electric field and was effective to obtain axially uniform coating on the inner surface of the tubes. The combination of hot-dipping aluminum and PEO process to obtain ceramic coating on 45# steel tubes was also performed in this work.

Hard films prepared by pulsed high energy density plasma (PHEDP) are characterized by high film/substrate adhesive strength, and high wear resistance. Titanium carbonitride (TiCN) films were deposited onto YG11C (ISO G20) cemented carbide cutting tool substrates by PHEDP at room temperature. XRD, XPS, SEM, AES, etc. were adopted to analyze the phases (elements) composition, microstructure and the interface of the films, respectively. The results show that, the uniform dense films are composed of grains ranging from 70 to 90 nm. According to the AES result, there is a broad transition layer between the film and the substrate, due to the ion implantation effect of the PHEDP. The transition layer is favorable for the film/substrate adhesion.

A new method for inner surface modification of steel tubes, named a combined technique of hot-dipping and plasma electrolytic oxidation (PEO) was proposed and demonstrated in this paper. In this work, metallurgically bonded ceramic coatings on inner surface of steel tubes were obtained using this method. In the combined process, aluminum coatings on steel were firstly prepared by the hot-dip process and then metallurgically bonded ceramic coatings were obtained on the aluminum coatings by PEO. The element distribution, phase composition and morphology of the aluminide layer and the ceramic coatings were characterized by SEM/EDX and XRD. The corrosion resistance of the ceramic coatings were also studied. The results show that, after hot-dip treatment, the coating layers consist of two layers, where Al, Fe x Al (1− x ) were detected from external topcoat to the aluminide/steel substrate. Then after PEO process, uniform Al 2 O 3 ceramic coatings have been deposited on inner surface of steel tubes. The ceramic coatings are mainly composed of α-Al 2 O 3 and γ-Al 2 O 3 phase. The compound coatings show favorable corrosion resistance property. The investigations indicate that the combination of hot-dipping and plasma electrolytic oxidation proves a promising technique for inner surface modification of steel tubes for protective purposes.

A mechanical model of a laser transformation hardening specimen with a crack in the middle of the hardened layer is developed to quantify the effects of the residual stress and hardness gradient on crack driving force in terms of J-integral. It is assumed that the crack in the middle of the hardened layer is created after laser transformation hardening. Using a Double Cantilever Beam model, the analytic solutions, which can be used to quantify the effects of the residual stress and the hardness gradient resulting from laser transformation hardening on crack driving force, are obtained. A numerical example shows the crack driving force decrease is very sensitive to the residual compressive stress increase.

Plasma electrolytic oxidation (PEO) is a cost-effective technique that can be used to prepare ceramic coatings on metals such as Ti, Al, Mg, Nb, etc., and their alloys, but this promising technique cannot be used to modify the surface properties of steels, which are the most widely used materials in engineering. In order to prepare metallurgically bonded ceramic coatings on steels, a combined technique of arc spraying and plasma electrolytic oxidation (PEO) was adopted. In this work, metallurgically bonded ceramic coatings on steels were obtained using this method. We firstly prepared aluminum coatings on steels by arc spraying, and then obtained the metallurgically bonded ceramic coatings on aluminum coatings by PEO. The characteristics of duplex coatings were analyzed by X-ray diffractometer (XRD) and scanning electron microscopy (SEM). The corrosion and wear resistance of the ceramic coatings were also studied. The results show that, duplex Al2O3/aluminum coatings have been deposited on steel substrate after the combined treatment. The ceramic coatings are mainly composed of alpha-Al2O3, gamma-Al(2)o(3), theta-Al2O3 and some amorphous phase. The duplex coatings show favorable corrosion and wear resistance properties. The investigations indicate that the combination of arc spraying and plasma electrolytic oxidation proves a promising technique for surface modification of steels for protective purposes. (c) 2005 Elsevier B.V. All rights reserved.

The in-situ titanium nitride (TiN) coating with a great thickness was reactive plasma sprayed in a nitrogen-containing environment. The microhardness of the coating was measured, and the indentations were used to determine the fracture toughness of the coating. The toughening mechanism was characterized by analyzing the SEM morphologies of TiN coating's fracture surfaces. Results show that the coating possesses a high hardness and toughness. The average hardness of the coating is 1200H(V) (100) (g); and the fracture toughness (K-IC) of it is 4.51 MPa center dot m(0.5). The cross-section of the TiN coating shows an obvious phenomenon of indentation size effect (ISE). The toughening mechanisms of the coating are crack deflection and pores, etc. (c) 2004 Elsevier B.V. All rights reserved.

Surface rapid solidification microstructures of AISI 321 austenitic stainless steel and 2024 aluminum alloy have been investigated by electron beam remelting process and optical microscopy observation. It is indicated that the morphologies of the melted layer of both stainless steel and aluminum alloy change dramatically compared to the original materials. Also, the microstructures were greatly refined after the electron beam irradiation.