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A series of symmetrical 1,4-disubstituted buta-1,3-diynes is prepared with excellent yields (up to 95%) through homocoupling of terminal alkynes catalyzed by a copper salt under solvent-free conditions. This method provides an environmentally friendly process to prepare 1,3-diynes in short reaction times under mild conditions. Furthermore, the method is suitable for a wide substrate scope and has excellent functional group compatibility. The reaction can also be scaled up to gram level.

Metal–organic framework (MOF) derivatives are among the most promising catalysts for the hydrogen evolution reaction (HER) for clean hydrogen energy production. Herein, we report the in situ synthesized MOF-derived CoPO hollow polyhedron nanostructures by simultaneous high temperature annealing and Ar–N2 radio frequency plasma treatment in the presence of a P precursor and subsequent oxygen incorporation from open air at lower temperature. The optimum Ar–N2 gas flow rates are used to precisely tune the P/O ratio, cut Co bonds within the MOFs and reconnect Co with P. Consequently, both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance are enhanced. Meanwhile, the filling of P elements can effectively change the electronic structure around the catalyst to ensure the uniform distribution of catalytically active sites. The resultant CoPO hollow nanocages with large specific surface areas show excellent bifunctional electrocatalytic activity towards both HER and OER with a low overpotential of 105 and 275 mV and a small Tafel slope of 48 and 52 mV dec−1, respectively. Our results open a new avenue for precise plasma-assisted engineering of MOF-derived hybrid hetero-structured electrocatalysts with rich oxygen vacancies and P dopants to simultaneously boost both half reactions in water electrolysis.

Nanostructured trimetallic phosphide electrocatalysts are promising for H2 and O2 evolution reactions (HER/OER) that are actively pursued nowadays to achieve commercial hydrogen production. Herein, a dual-functional Nb-doped NiFe phosphide nanosheet catalyst with a low cost and high stability was successfully prepared on nickel foam (NF) pretreated with dielectric barrier discharge (DBD) plasmas (PNF) operated under ambient conditions. The resulting Ni12P5–Fe2P–NbP layered nanosheets on the PNF show exceptional catalytic performances, evidenced by their low overpotentials for delivering current densities of 100 and 400 mA cm−2 (j100/j400) of only 178 and 265 mV for the HER, and 280 and 330 mV for the OER, as well as the small Tafel slope values of 52 (HER) and 59 (OER) mV dec−1, respectively. The catalyst also exhibits a good electrocatalytic durability and stability during 100 h continuous HER and OER tests at j300. Moreover, the current densities of 10 and 100 mA cm−2 are achieved at low cell voltages of 1.51 and 1.65 V, thus outperforming most of the reported electrocatalysts in two-electrode alkaline water electrolyzers. Numerical simulation analysis shows that the Ni and Nb atoms in the Ni12P5–Fe2P–NbP nanostructures are the key factors responsible for the achieved excellent performance in water electrolysis.

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.

Total saponins extracted from Dioscorea collettii (TSD), extracts of the Chinese herb Dioscorea, are thought to exhibit therapeutic benefit in gouty arthritis. However, its exact mechanism remains unclear. The current study aimed to elucidate the underlying mechanisms by investigating the effects of TSD on the inflammation induced by monosodium urate (MSU) crystals in THP-1 macrophages. The viability of THP-1 macrophages was examined using the MTT assay and the levels of inflammatory cytokines, including interleukin (IL)-1β, IL-18 and tumor necrosis factor (TNF)-α, released by the cells were quantitatively measured using ELISA kits. The results revealed that the protein level of cluster of differentiation 11b increased in THP-1 cells treated with 100 ng/ml phorbol ester, suggesting that monocytic THP-1 cells were successfully differentiated into macrophages. TSD decreased the levels of inflammatory cytokines, including TNF-α, IL-18 and IL-1β, secreted by THP-1 macrophages. As the release of IL-1β and IL-18 is dependent on the NLR family pyrin domain containing 3 (NALP3) inflammasome and caspase-1, the current study investigated the effect of TSD on the aforementioned proteins. The results revealed that TSD decreased the protein levels of NALP3 and apoptosis-associated speck-like, which serve important roles in the assembly of the NALP3 inflammasome. Furthermore, NALP3 inflammasome-related proteins were also decreased by TSD in rotenone induced THP-1 macrophages, TSD inhibited the activation of caspase-1 and rotenone-induced NALP3 inflammasome activation in THP-1 macrophages. The results obtained in the current study revealed that TSD attenuated MSU crystal-induced inflammation by inhibiting rotenone-induced activation of the NALP3 inflammasome and caspase-1, suggesting that these two proteins may be novel targets for the treatment of gouty arthritis.

Electrochemical water splitting is one of the most promising ways for clean hydrogen energy production. Along with using earth-abundant, atomically engineered catalysts that are highly active and stable, clean, chemical-waste-free catalyst production—using minimum resources—is a major hurdle toward achieving zero-carbon-emission commercial operations. Herein, we propose a clean way to fabricate NiSe2–CoSe2 on nickel–cobalt foam (NCF) using pure water for the in situ sprouting of NiCo layered double hydroxide (LDH) precursors. The excellent electrocatalytic activity for overall water splitting in alkaline electrolytes is highlighted by the overpotentials of NiSe2–CoSe2/NCF for delivering current densities of 10 and 400 mA cm−2 (j10 and j400, respectively) at only 24 and 257 mV for hydrogen evolution reaction (HER) and 250 and 346 mV for oxygen evolution reaction (OER), as well as the fast reaction kinetics affording small Tafel slope values of 24 (HER) and 48 (OER) mV dec−1, respectively. NiSe2–CoSe2/NCF exhibits excellent electrocatalytic performance and structural stability, evidenced by the unchanged polarization curve after 104 cycles of CV tests and low decay of high current density (j100) after 100 h of HER and OER measurements. Theoretical analysis revealed that the Co atoms dispersed on the heterointerfaces between the NiSe2 and CoSe2 phases act as the electrocatalytic sites.

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 is a source of sustainable and clean energy poised to replace fossil fuels. Bifunctional electrocatalysts are actively pursued to simultaneously drive the two key reactions, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), for hydrogen production by electrolysis water. One of the most promising candidates based on bimetallic layered double hydroxide salts (LHSs) and cobalt-based organic framework (ZIF-67) suffer from poor interface coupling. Herein, we present a new approach based on fusing NiCo LHSs nanowire arrays with ZIF-67 to fabricate three-dimensional flower-like structures on a Ni-Fe foam support. To improve interfacial coupling and catalytic performance, simple oxidation, carbonization, sulfurization, and selenization are performed to study the effects of different post-treatments and discover the optimum bifunctional electrocatalysts. The optimized S-doped catalyst reveals the highest electrocatalytic characteristic quantified by the low overpotentials of 170 and 100 mV for OER and HER at 10 mA cm -2 in 1 M KOH, respectively. This outstanding electrocatalytic property is ascribed to strong interfacial coupling between the NiCo-LHSs and ZIF-67 derivatives, as well as the rational electronic structures, dense catalytic active sites, and large specific surface area. This work opens new prospects for fabricating efficient and low-cost electrocatalysts for renewable hydrogen energy production.

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.

Background: Glioblastomas (GBMs) are grade IV central nervous system tumors characterized by a poor prognosis and a median overall survival of 15 months. The glioblastoma cell population is more genetically unstable, resistant to chemotherapy, more angiogenic, and more malignant. Because ubiquitin-specific proteases (USPs) remove ubiquitin from oncogenic protein substrates, effective inhibition of ubiquitin-specific protease 7 (USP7), which is highly expressed in GBMs, is a potentially critical therapeutic approach. Methods: Immunohistochemistry and Western blotting were used to detect high expression of USP7 in GBM. in vitro studies were performed by Western blotting, immunofluorescence, and flow cytometry to detect apoptosis following inhibition of USP7. Anti-apoptotic substrates of USP7 were defined by Co-IP and TMT proteomics. Nude mouse intracranial xenograft models were constructed to verify whether inhibition of USP7 inhibited the proliferation rate of tumours.Results: USP7 is significantly upregulated in glioblastoma samples. Interfering with USP7 in GBMs induced significant apoptosis, which also occurred after treatment with P5091, a novel small molecule inhibitor of USP7. Mechanistically, apoptosis of GBMs after interference with USP7 function is achieved by stabilizing a key anti-apoptotic protein, ADP-ribosylation factor 4 (ARF4).Furthermore, USP7 interacts directly with ARF4 and catalyzes the removal of the K48-linked polyubiquitinated chain that binds to ARF4, thereby stabilizing the protein. In in vivo experiments, P5091 significantly inhibited tumor growth and promoted the expression of apoptotic genes. Conclusion: Targeted inhibition of USP7 enhances the ubiquitination of ARF4 and ultimately mediates the apoptosis of GBM cells. In a clinical sense, P5091 as a specific inhibitor of USP7 may be an effective approach for the treatment of GBM.

Background Glioblastomas (GBMs) are grade IV central nervous system tumors characterized by a poor prognosis and a short median overall survival. Effective induction of GBM cell death is difficult because the GBM cell population is genetically unstable, resistant to chemotherapy and highly angiogenic. In recent studies, ubiquitin-specific protease 7 (USP7) is shown to scavenge ubiquitin from oncogenic protein substrates, so effective inhibition of USP7 may be a potential key treatment for GBM. Methods Immunohistochemistry and western blotting were used to detect the expression of USP7 in GBM tissues. In vitro apoptosis assay of USP7 inhibition was performed by western blotting, immunofluorescence, and flow cytometry. Anti-apoptotic substrates of USP7 were defined by Co-IP and TMT proteomics. Western blotting and IP were used to verify the relationship between USP7 and its substrate. In an in vivo experiment using an intracranial xenograft model in nude mice was constructed to assess the therapeutic effect of target USP7. Results Immunohistochemistry and western blotting confirmed that USP7 was significantly upregulated in glioblastoma samples. In in vitro experiments, inhibition of USP7 in GBM induced significant apoptosis. Co-IP and TMT proteomics identified a key anti-apoptotic substrate of USP7, ADP-ribosylation factor 4 (ARF4). Western blotting and IP confirmed that USP7 interacted directly with ARF4 and catalyzed the removal of the K48-linked polyubiquitinated chain that binded to ARF4. In addition, in vivo experiments revealed that USP7 inhibition significantly suppressed tumor growth and promoted the expression of apoptotic genes. Conclusions Targeted inhibition of USP7 enhances the ubiquitination of ARF4 and ultimately mediates the apoptosis of GBM cells. In a clinical sense, P5091 as a novel specific inhibitor of USP7 may be an effective approach for the treatment of GBM.

Developing highly active electrocatalysts with rich oxygen vacancies and precisely distributed metal sites holds exceptional promise for various renewable and sustainable energy technologies. However, the great challenge is to ensure the stability of oxygen vacancies (VO) during the oxygen evolution reaction (OER) process. Herein, we implement an innovative approach to produce a highly active and stable OER electrocatalyst by plasma-enabled Fe doping of Co-based 2D metal–organic framework (MOF) nanosheets, followed by a carbonization process to fabricate unique triangular-shaped “cheese-like” Fe/Co–carbon nanosheets with a mesoporous structure, and densely and evenly distributed reactive centers, and without damaging the frameworks. The O2–Ar radio frequency (RF) plasma ensured two critical effects, namely oxygen vacancy generation, and forming and modifying the oxidation states of the catalytically active metals in the framework leading to high OER performance. It is shown that filling the oxygen vacancies with Fe heteroatoms helps tune the atomic sites of the two metals in the MOFs and achieve a unique heterostructure where electron currents can be directed between metal sites of different oxidation states. Benefiting from the demonstrated unique advantages of our plasma-enabled approach, the optimized Fe1Co3/VO-800 exhibits a significantly enhanced OER performance and long-term stability, evidenced by a low overpotential of 260 mV at 10 mA cm−2 and a small Tafel slope of 53 mV dec−1. This work provides a new effective approach for the development of next-generation electrocatalysts for diverse applications in environmental and energy fields.

Buparlisib is a selective phosphoinositide 3 kinase inhibitor currently evaluated in clinical trials. We developed and validated an LC-MS/MS coupled with a one-step protein precipitation extraction method for the quantitation of buparlisib in rat plasma. After protein precipitation with acetonitrile, the plasma sample was analyzed using a Cortecs UPLC C18 column, with acetonitrile-0.1% formic acid as the mobile phase system. Mass spectrometric detection was conducted in positive ionization mode, with target quantitative ion pair of m/z 411.2 → 367.2 for buparlisib. The calibration curve showed good linearity (1.0-3000 ng/ml), with acceptable accuracy (RE ranging from -6.2 to 5.9%) and precision (RSD within 8.2%) values at quality control concentrations. Extraction recovery from plasma was 80.9-88.7% and the matrix effect was negligible (92.6-95.2%). The validated method presented a simple quantification method of buparlisib in detail and utilized it for a pharmacokinetic study at three dose concentrations after oral administration in Wistar rats.

Rational design of noble-metal-free electrocatalysts with excellent performance for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is critical for next-generation industrial applications of water electrolysis. Here, a simple and robust preparation method of three-dimensional (3D) nanostructured catalysts made of abundant metals is presented. The 3D hydrangea-like microspheres made of nickel–vanadium double hydroxide nanosheets are first prepared on the Ni–Co foam (NCF) followed by the hydroxides exchange with (MoS4)2– ions to form Chevrel-phase Ni–V–Mo sulfide. Benefiting from the 3D holey nanostructures with a large surface area, low adsorption free energy values, and fast electronic transport, the overpotentials of the optimized Ni8V2(Mo3S4)11/NCF catalyst for HER and OER at a current density 10 mA cm–2 are as low as 129 and 330 mV, respectively. The amounts of H2 and O2 generated at a current density of 10 mA cm–2 are about 517 and 342 μmol h–1, which is very competitive wit...

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.

The promising potential of photodynamic therapy (PDT) has fueled the development of minimally invasive therapeutic approaches for cancer therapy. However, overcoming limitations in PDT efficacy in the hypoxic tumor environment and light penetration depth remains a challenge. We report the engineering of tungsten carbide nanoparticles (W2C NPs) for 1,064 nm laser-activated dual-type PDT and combined theranostics. The synthesized W2C NPs allow the robust generation of dual-type reactive oxygen species, including hydroxyl radicals (type I) and singlet oxygen (type II), using only single 1,064 nm laser activation, enabling effective PDT even in the hypoxic tumor environment. The W2C NPs also possess high photothermal performance under 1,064 nm laser irradiation, thus enabling synergistically enhanced cancer therapeutic efficacy of PDT and photothermal therapy. Additionally, the photoacoustic and X-ray computed tomography bioimaging properties of W2C NPs facilitate the integration of tumor diagnosis and therapy. The developed W2C based theranostic nanoagents increase the generation of reactive oxygen species in hypoxic tumors, improve the light penetration depth, and facilitate combined photothermal therapy and photoacoustic/computed tomography dual-mode bioimaging. These attributes could spur the exploration of transition metal carbides for advanced biomedical applications.

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.

In the treatment of resistant hypertension, physiologically individualized therapy based on phenotyping with plasma renin activity (PRA) and plasma aldosterone significantly improves blood pressure control. Patients with a low-renin/low aldosterone (Liddle) phenotype respond best to amiloride, while those with low-renin/high aldosterone respond best to aldosterone antagonists, and those with high renin/high aldosterone (renal phenotype) respond best to angiotensin receptor blockers (ARB). However, it is important to measure PRA in a stimulated condition to distinguish between low levels due to high salt intake, licorice or nonsteroidal inflammatory drugs and low levels due to suppression by excess aldosterone secretion or renal tubular genetic variants causing retention of salt and water (Liddle phenotype). In the past, both diuretics and angiotensin converting inhibitors (ACEi) have been used for this purpose, and it has been assumed that these classes of drugs are equivalent. In this study of 2896 patients with hypertension, we evaluated that assumption. We found important differences among diuretics alone, ACEi/ARB alone, and ACEi/ARB + diuretics, which all stimulated PRA. However, ACEi/ARB lowers plasma aldosterone, and beta blockers lower PRA. Among patients with systolic pressure ≥ 180 mmHg ± diastolic pressure ≥ 100 mmHg stimulated only by diuretics, the phenotypes were 25% Liddle, 38% IA, 8.7% renal, and 28.3% mixed. In choosing physiologically individualized therapy based on PRA and aldosterone, it is important to consider the classes of stimulating drugs. Phenotypes are best distinguished by taking into account the aldosterone/PRA ratio in addition to the levels of PRA and aldosterone.

We report a facile method by which to synthesize Au/Cdot nanohybrids using carbon dots (Cdots) obtained from rice straw as a direct reducing agent as well as a stabilizer. Rice-straw-derived Cdots possess oxygen-containing functional groups that act as an electron-donating source to reduce Au3+ to Au0 without the use of chemical reagents for the reduction of Au precursors. Additionally, the strong Au-carbon interaction promotes a high electron transfer of the Au/Cdot nanohybrid electrocatalyst, resulting in enhanced performance of the hydrogen evolution reaction (HER). The overpotential is 150 mV at a current density of 10 mA·cm−2 and the TOF value is 0.06·s−1, representing the most outstanding HER performance among Au-based catalysts as a non-Pt HER electrocatalyst. The HER activity is stably maintained for 2000 cycles as well as for 48 h. The synthesis of Cdots, the hybridization of Au/Cdot electrocatalyst, and the production of clean hydrogen fuel using Au/Cdots are zero CO2 emission strategies, not only preventing the emission of pollutants but also satisfying the energy needs of humankind.

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.

Bimetallic phosphate electrocatalysts on carbon-cloth support are among the most promising industry-relevant solutions for electrocatalytic hydrogen production. To address the persistent issue of hetero-phase interfacing on carbon support while ensuring high activity and stability, a low-cost, high-performance hydrogen evolution reaction (HER) electrocatalyst is developed. Bi-phase Ni12P5-Ni4Nb5P4 nanocrystals with rich heterointerfaces and phase edges are successfully fabricated on carbon cloth (CC), which is enabled by intentional defect creation by atmospheric pressure dielectric barrier discharge (DBD) plasma (PCC). The obtained Ni12P5-Ni4Nb5P4/PCC electrocatalyst exhibits excellent HER performance, heralded by the low overpotentials of 81 and 287 mV for delivering current densities of 10 (j10) and 500 (j500) mA cm−2, respectively. Meanwhile, the Ni12P5-Ni4Nb5P4/PCC maintains spectacular catalytic activity at high current density region (>j615), which outperformed the industry-relevant benchmark Pt/C/PCC catalyst. The catalyst grown on the plasma-treated support shows remarkably longer operation and ultra-stable electrocatalytic characteristics over 100 h continuous operation. Ab initio numerical simulations reveal that Ni atoms exposed in the heterointerfaces act as the main catalytically active centers for HER.

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.

Semiconductor nanostructures have received considerable attention in the field of photocatalytic hydrogen evolution. However, eco-friendly, high efficiency, and low-cost semiconductor materials are still desired. In consideration of this, herein, we design a new and economic noble-metal-free CdS/ZnxCo3-xO4 (CdS/ZCO) nanohybrid photocatalyst using a metal-organic framework (MOF) template, which is a framework structure composed of organic ligands and metal ion nodes with different numbers of connections. The as-prepared CdS/ZCO composites with a large specific surface area and porous hollow structure exhibit remarkable catalytic activity and high stability for hydrogen generation. The hydrogen evolution rate is about 3978.6 μmol g-1 h-1 with lactic acid as the sacrificial agent when the optimized amount of CdS nanoparticles (30 wt%) is decorated on the ZCO frame, and the production efficiency of H2 for CdS/ZCO is 4 times higher than that for CdS nanospheres or CdS/Co3O4. The significantly enhanced photocatalytic activity of CdS/ZCO is attributed to the efficient charge separation and transfer between the phase boundary of CdS and ZCO. In addition, the composites exhibit better hydrogen production in lactic acid than in methanol, and the remarkable catalytic activity and high stability of the CdS/ZCO composites for hydrogen evolution indicate that MOF-based composite materials have potential application prospects in energy conversion.

A novel method for the preparation of composites based on poly(vinyl alcohol) (PVA) and micro- and nano-fibrillated cellulose (M/NFC) is reported. The addition of crosslinking HEMA monomers and a photo-initiator enabled the formation of an interpenetrated polymer network that displayed enhanced interfacial adhesion and dispersion of (M/NFC) in the matrix. Photo-crosslinked PVA/(M/NFC)/polyHEMA composite films produced by casting followed by UV polymerization of HEMA were characterized by using several approaches. These included Fourier transform infrared and UV–Vis spectroscopies, differential scanning calorimetry, X-ray diffractometry, thermogravimetric analysis and dynamic mechanical analysis. The thermo-mechanical and optical properties as well as water absorption and vapor barrier abilities of the developed photo-crosslinked PVA/(M/NFC)/polyHEMA films were measured and the benefit of photo-crosslinking determined. The major degradation peak of photo-crosslinked PVA/(M/NFC)/polyHEMA composites increased substantially compared to that of the PVA/(M/NFC) system (from ~300 to ~350 °C). The water vapor permeability of PVA/(M/NFC)/polyHEMA composite films was reduced with HEMA loading (5.44 × 10−11, 5.10 × 10−11, 4.12 × 10−11, 4.31 × 10−11 g/m h Pa for 0, 5, 10 and 15 % HEMA, respectively). Overall, a new and facile method for the synthesis of PVA/(M/NFC)-based composite networks interpenetrated with cross-linked poly(HEMA) is demonstrated, offering excellent prospects for packaging 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.

In this paper, we present a large area nanosecond pulse gas-liquid diffuse discharge plasma with small flow rate of helium as working gas. The discharge images, the waveforms of pulse voltage & current, the emission spectra, and the gas temperature are measured or calculated. As a energy-efficient sterilization for sewage, the efficiency of sewage sterilization in both static liquid and flowed liquid are investigated. It is found that an optimal value of helium gas flow rate in the production of reactive oxygen species (OH, O) can be obtained when the He flow rate is 5mlmin � 1 , under this condition, high inactivation efficiencies of bacteria and fungus can be presented.

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.

In this paper, the different discharge and polymerizing characteristics of Ar and He atmospheric pressure plasma jets (APPJs) were studied. The as-deposited polymer of acrylic acid (PAA) on silk fibroin film (SFF) by APPJs with Ar/O2 and He/O2 gases is investigated with AFM, FESEM and XPS. Optical emission spectroscopy (OES) measurements indicated that various reactive radicals, such as OH and O as well as some acrylic acid (AA) particles existed in the plasma jets. AFM images showed that the He/O2 plasma-deposited films had the most homogeneous characteristics and good water resistance properties. The cross-sections of silicon substrates obtained by FESEM showed that the deposition rates of PAA were 50 nm center dot min1 and 15nm center dot min1 for Ar/O2 and He/O2 plasmas, respectively. Also, according to XPS analysis, He/O2 plasma created a higher concentration of carboxyl groups on the deposited film than when Ar/O2 plasma was used.

Objective The current study aimed to investigate whether the saponins, bioactive component of effects of D. collettii , could reduce the serum uric acid level in a hyperuricemic mouse via regulation of urate transporters. Methods Chronic hyperuricemia model was established by combine administration of adenine (100 mg/kg) and ethambutol (250 mg/kg). In the model group, the serum uric acid (SUA), urine uric acid (UUA) volume, and 24-h UUA values increased significantly, while the uric acid clearance rate (CUr) and creatinine clearance rate (CCr) values decreased. Further, the model groups showed significantly lower expression of organic anion transporter 1 (OAT1) and organic anion transporter 3 (OAT3) and significantly higher expression of renal tubular urate transporter 1 (URAT1), glucose transporter 9 (GLUT9) and URAT1 mRNA than the normal control group. Results Saponins administration was found to have a dose-dependent effect, as evidenced by the increase in the 24-h UUA, CUr and CCr values; the decrease in SUA; the decrease in the renal expression of URAT1 mRNA and URAT1 and GLUT9 proteins; and the increase in the renal expression of the OAT1 and OAT3 proteins. Conclusion The saponins extracted from D. collettii rhizomes had an obvious anti-hyperuricemic effect through downregulation of the URAT1 mRNA and the URAT1 and GLUT9 proteins and upregulation of the OAT1 and OAT3 proteins.

The aim of this work is to coat silk fibers (SF) with polymer of acrylic acid (PAA) using an atmospheric pressure glow discharge (APGD) plasma jet in order to immobilize antimicrobial peptide LL-37. The polymer properties are characterized by contact angle goniometry (CAG), XPS, AFM and SEM. The CA of the SF film can be decreased to 340, and the surface roughness of PAA in the center of plasma jet is larger than in other areas. Compared with the original SF, the concentration of carboxyl group increases greatly when the SF are modified by Ar plasma jet polymerization of AA. The augmentation of functional groups is very useful to immobilize larger concentrations of microbial peptide LL-37 on the SF surface, and the satisfactory antimicrobial activity on inhibiting the Escherichia coli (E. coli) is thereby achieved.

Presently noninvasive methods were employed to the diagnosis of nonalcoholic fatty liver disease (NAFLD), including fatty liver index (FLI), hepatic steatosis index (HSI), product of fasting triglyceride and glucose levels (TyG), and single nucleotide polymorphism (SNP), whereas the accuracy of those indexes need to be improved. Our study aimed to investigate the feasibility of a new index comprehensive index (CI), consisting of 6 serum biomarkers and anthropometric parameters through multivariate logistic regression analysis, to the earlier detection of NAFLD, and the diagnostic value of 5 SNPs (S1: rs2854116 of apolipoprotein C3 [APOC3], S2: rs4149267 of ATP-binding cassette transporter [ABCA1], S3: rs13702 of lipoprotein lipase [LPL], S4: rs738409 of protein 3 [patatin-like phospholipase domain containing protein 3 (PNPLA3)], S5: rs780094 of glucokinase regulatory protein gene [GCKR]) for NAFLD were also explored. Area under the receiver operating characteristic curves (AUROC) and Youden index (YI) were calculated to assess the diagnostic value. The AUROC of CI was higher than FLI, HSI, and TyG (CI: 0.897, FLI: 0.873, HSI: 0.855, TyG: 0.793). Therefore, CI might be a better index for the diagnosis of NAFLD. Although there had no statistical significance (P = .123), the AUROC and YI were increased when CI combined with rs2854116 (S1) (AUROC = 0.902, YI = 0.6844). The combination of CI with S1 showed even better diagnostic accuracy than CI, which suggests the potential value of rs2854116 for the diagnosis of NAFLD.

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.

(Ti,Ta)N films were prepared by pulsed high energy density plasma (PHEDP) from a coaxial gun in N2 gas. The coaxial gun is composed of a tantalum inner electrode and a titanium outer one. Material characteristics of the (Ti,Ta)N film were investigated by x-ray photoelectron spectroscopy and x-ray diffraction. The microstructure of the film was observed by a scanning electron microscope. The elemental composition and the interface of the film/substrate were analysed using Auger electron spectrometry. Our results suggest that the binary metal nitride film, (Ti,Ta)N, can be prepared by PHEDP. It also shows that dense nanocrystalline (Ti,Ta)N film can be achieved.

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.

The pulsed high energy density plasma (PHEDP) is generated in the working gas due to a high-voltage high-current discharge, within a coaxial gun. In PHEDP surface modification, discharge is applied for preparing the amorphous and nanostructured high-melting materials as thin films deposited on various substrates. In this investigation, Ta(C)N films were deposited using PHEDP on stainless steel. Pure tantalum and graphite were used as the inner and outer electrodes of the PHEDP coaxial gun, respectively. Nitrogen was used as the working gas and also one of the reactants. Preliminary study on the films prepared under different conditions shows that the formation of Ta(C)N is drastically voltage dependent. At lower gun voltage, no Ta(C)N was detected in the films; when the gun voltage reaches or exceeds 3.0 kV, Ta(C)N occurred. The films are composed of densely stacked nanocrystallines with diameter less than 30 nm, and some grains are within 10 nm in diameter.

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 novel atmospheric pressure plasma fluidized bed (APPFB) with one liquid electrode was designed, and its preliminary discharge characteristics were studied. The glow discharge in the APPFB was generated by applying a low power with helium (He) gas, and the plasma gas temperature was no higher than 320 K when the applied power was lower than 11 W. The plasma optical emission spectrum (OES) of the gas mixture consisting of He and hexamethyldisiloxane (HMDSO) was recorded by a UV-visible monochromator. The calcium carbonate powders were modified by APPFB using HMDSO in the He plasma. The powder surface energy was decreased greatly by coating an organosilicon polymer onto the powder surface. This surface modification process changed the wettability of the powder from super-hydrophilicity to super-hydrophobicity, and the contact angle of water on the modified powders surface was greater than 160°.

An atmospheric pressure glow discharge plume (APGD-p) using a dielectric barrier discharge reactor with one conductive liquid electrode was designed in our study. The preliminary characteristics of the plume and application in the degradation of a dye, methyl violet 5BN (MV-5BN), were presented in this paper. The APGD reactor produced a cold plasma plume with temperature not higher than 320 K at power 5 - 50 W. The MV- 5BN solution as a probe for dye wastewater was treated by the downstream gases of the plasma plume. The results indicated that the active argon (Ar) and nitrogen (N-2) gases had little effect on the MV- 5BN degradation, but the air and oxygen (O-2) gas depleted the organic molecules effectively. In particular, the downstream O-2 gas degraded the dye molecules entirely.

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.