Facile bioactive transformation of magnesium alloy surfaces for surgical implant applications.

The market for orthopedic implant alloys has seen significant growth in recent years, and efforts to reduce the carbon footprint of medical treatment (i.e., green medicine) have prompted extensive research on biodegradable magnesium-based alloys. Magnesium alloys provide the mechanical strength and biocompatibility required of medical implants; however, they are highly prone to corrosion. In this study, Mg-9Li alloy was immersed in cell culture medium to simulate degradation in the human body, while monitoring the corresponding effects of the reaction products on cells. Variations in pH revealed the generation of hydroxyl groups, which led to cell death. At day-5 of the reaction, a coating of MgCO3 (H2O)3, HA, and α -TCP appeared on sample surfaces. The coating presented three-dimensional surface structures (at nanometer to submicron scales), anti-corrosion effects, and an altered surface micro-environment conducive to the adhesion of osteoblasts. This analysis based on bio-simulation immersion has important implications for the clinical use of Mg alloys to secure regenerated periodontal tissue.

Biocompatibile nanofiber based membranes for high-efficiency filtration of nano-aerosols with low air resistance.

Particulate matter (PMs) from combustion emissions (traffic, power plant, and industries) and the novel coronavirus (COVID-19) pandemic have recently enhanced the development of personal protective equipment against airborne pathogens to protect humans' respiratory system. However, most commercial face masks still cannot simultaneously achieve breathability and high filtration of PMs, bacteria, and viruses. This study used the electrospinning method with polyimide (PI) and polyethersulfone (PES) solutions to form a nanofiber membrane with low-pressure loss and high biocompatibility for high-efficiency bacteria, viruses, and nano-aerosol removal. Conclusively, the optimized nano-sized PI/PES membrane (0.1625 m2/g basis weight) exhibited conspicuous performance for the highest filtration efficiency towards PM from 50 to 500 nm (99.74 %), good filter quality of nano-aerosol (3.27 Pa-1), exceptional interception ratio against 100-nm airborne COVID-19 (over 99 %), and non-toxic effect on the human body (107 % cell viability). The PI/PES nanofiber membrane required potential advantage to form a medical face mask because of its averaged 97 % BEF on Staphylococcus aureus filiation and ultra-low pressure loss of 0.98 Pa by referring ASTM F2101-01. The non-toxic PI/PES filters provide a new perspective on designing excellent performance for nano-aerosols from air pollution and airborne COVID-19 with easy and comfortable breathing under ultra-low air flow resistance.

Carbon Dioxide Tornado-Type Atmospheric-Pressure-Plasma-Jet-Processed rGO-SnO2 Nanocomposites for Symmetric Supercapacitors.

Pastes containing reduced graphene oxide (rGO) and SnCl2 solution were screen printed on carbon cloth and then calcined using a CO2 tornado-type atmospheric-pressure plasma jet (APPJ). The tornado circulation of the plasma gas enhances the mixing of the reactive plasma species and thus ensures better reaction uniformity. Scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) were performed to characterize the synthesized rGO-SnO2 nanocomposites on carbon cloth. After CO2 tornado-type APPJ treatment, the pastes were converted into rGO-SnO2 nanocomposites for use as the active electrode materials of polyvinyl alcohol (PVA)-H2SO4 gel-electrolyte flexible supercapacitors (SCs). Various APPJ scanning times were tested to obtain SCs with optimized performance. With seven APPJ scans, the SC achieved the best areal capacitance of 37.17 mF/cm2 in Galvanostatic charging/discharging (GCD) and a capacitance retention rate of 84.2% after 10,000-cycle cyclic voltammetry (CV) tests. The capacitance contribution ratio, calculated as pseudocapacitance/electrical double layer capacitance (PC/EDLC), is ~50/50 as analyzed by the Trasatti method. GCD data were also analyzed to obtain Ragone plots; these indicated an energy density comparable to those of SCs processed using a fixed-point nitrogen APPJ in our previous study.

Effects of field scale in situ biochar incorporation on soil environment in a tropical highly weathered soil.

Biochar has been proven as a soil amendment to improve soil environment. However, mechanistic understanding of biochar on soil physical properties and microbial community remains unclear. In this study, a wood biochar (WB), was incorporated into a highly weathered tropical soil, and after 1 year the in situ changes in soil properties and microbial community were evaluated. A field trial was conducted for application of compost, wood biochar, and polyacrylamide. Microstructure and morphological features of the soils were characterized through 3D X-ray microscopy and polarized microscopy. Soil microbial communities were identified through next-generation sequencing (NGS). After incubation, the number of pores and connection throats between the pores of biochar treated soil increased by 3.8 and 7.2 times, respectively, compared to the control. According to NGS results, most sequences belonged to Anaerolinea thermolimosa, Caldithrix palaeochoryensis, Chthoniobacter flavus, and Cohnella soli. Canonical correlation analysis (CCA) further demonstrated that the microbial community structure was determined by inorganic N (IN), available P (AP), pH, soil organic C (SOC), porosity, bulk density (BD), and aggregate stability. The treatments with co-application of biochar and compost facilitated the dominance of Cal. palaeochoryensis, Cht. flavus, and Coh. soli, all of which promoted organic matter decomposition and ammonia oxidation in the soil. The apparent increases in IN, AP, porosity, and SOC caused by the addition of biochar and compost may be the proponents of changes in soil microbial communities. The co-application of compost and biochar may be a suitable strategy for real world biochar incorporation in highly weathered soil.

Dual RGD-immobilized poly(L-lactic acid) by atmospheric pressure plasma jet for bone tissue engineering.

Surface treatment on PLA substrates by atmospheric pressure plasma jet (APPJ) for polymerization of dual RGD-peptides were investigated. Peptide-modified surfaces have been highlighted as the most promising approach to improve the integration of implants into surrounding bones. By varying the RF power, PLA substrates treated by APPJ process have a tendency to form a hydrophobic surface. The effects on the proliferation and differentiation of MG63 cells were evaluated and osteocalcin (OCN) expression was analyzed using RT-PCR. The water contact angle of the W/APPJ process PLA was approximately 54% of that of the W/O APPJ process PLA substrates. W/APPJ process significantly increased cell proliferation, improved the functionality of the material without using a complicated procedure. We believe that pretreatment using the APPJ processes and dual RGD grafting can be more appropriate than traditional surface modification methods, with more potential for application to bone materials.

Fluoride at waste oyster shell surfaces - Role of magnesium.

Reaction of fluoride with waste oyster shell was studied. To enhance the stability and adsorption capacity, oyster shell was coated with Al(OH)3 and the adsorption behaviors were compared with the uncoated one. When at low fluoride concentration (<30 mg/L), fluoride removal efficiency decreased with increasing pH, and the adsorption could be modeled by Langmuir isotherm. At high fluoride concentration (>100 mg/L), linear adsorption isotherm fitted better, in which the adsorption capacity of fluoride increased linearly with increasing equilibrium fluoride concentration. The coated oyster shell showed higher adsorption capacity and wider workable pH range. From XPS analysis, the presence of CaF2 was confirmed by the peak at 684.7 eV when fluoride concentration increased. It was noted that magnesium content of waste oyster shell reacted with fluoride to form significant fractions of MgF2 whose corresponding peak was detected at 685.6-685.8 eV. For coated oyster shell, fluoride reacted with Ca, Mg, and Al. The reaction mechanism was mainly adsorption at low initial concentration, and precipitation-dominated at higher concentration.

Electric arc furnace dust as an alternative low-cost oxygen carrier for chemical looping combustion.

The relative abundance and low cost of electric arc furnace dust (EAFD) make it a viable oxygen carrier for chemical looping combustion (CLC) system. Under a reducing agent, zinc ferrite (ZnFe2O4) phase in EAFD releases zinc vapor in a complex gas-solid reaction. In an effort to suppress the emission of zinc vapor, the reaction mechanism of ZnFe2O4 prepared as an oxygen carrier in a redox cycling test is primarily discussed, as well as the issue of coupling with an inert Al2O3 support. The study focused the investigation on redox cycling behavior and CO2 conversion in ZnFe2O4/Al2O3 and EAFD/Al2O3 systems using a thermogravimetric analyzer (TGA) and fixed-bed reactor (FxBR). In a lab-scaled semi-fluidized bed reactor (semi-FzBR) of EAFD/Al2O3 as an oxygen carrier system, a high CO gas yield approximately 0.98 after fifty redox cycles is also experimentally obtained. It can be anticipated that the use of EAFD/Al2O3 system as an oxygen carrier in a reversible CLC process could be economical and environmentally beneficial.

Ascorbic Acid-Assisted Synthesis of Mesoporous Sodium Vanadium Phosphate Nanoparticles with Highly sp(2) -Coordinated Carbon Coatings as Efficient Cathode Materials for Rechargeable Sodium-Ion Batteries.

Herein, mesoporous sodium vanadium phosphate nanoparticles with highly sp(2) -coordinated carbon coatings (meso-Na3 V2 (PO4 )3 /C) were successfully synthesized as efficient cathode material for rechargeable sodium-ion batteries by using ascorbic acid as both the reductant and carbon source, followed by calcination at 750 °C in an argon atmosphere. Their crystalline structure, morphology, surface area, chemical composition, carbon nature and amount were systematically explored. Following electrochemical measurements, the resultant meso-Na3 V2 (PO4 )3 /C not only delivered good reversible capacity (98 mAh g(-1) at 0.1 A g(-1) ) and superior rate capability (63 mAh g(-1) at 1 A g(-1) ) but also exhibited comparable cycling performance (capacity retention: ≈74 % at 450 cycles at 0.4 A g(-1) ). Moreover, the symmetrical sodium-ion full cell with excellent reversibility and cycling stability was also achieved (capacity retention: 92.2 % at 0.1 A g(-1) with 99.5 % coulombic efficiency after 100 cycles). These attributes are ascribed to the distinctive mesostructure for facile sodium-ion insertion/extraction and their continuous sp(2) -coordinated carbon coatings, which facilitate electronic conduction.

Alginate/Poly(γ-glutamic Acid) Base Biocompatible Gel for Bone Tissue Engineering.

A technique for synthesizing biocompatible hydrogels by cross-linking calcium-form poly(γ-glutamic acid), alginate sodium, and Pluronic F-127 was created, in which alginate can be cross-linked by Ca(2+) from Ca-γ-PGA directly and γ-PGA molecules introduced into the alginate matrix to provide pH sensitivity and hemostasis. Mechanical properties, swelling behavior, and blood compatibility were investigated for each hydrogel compared with alginate and for γ-PGA hydrogel with the sodium form only. Adding F-127 improves mechanical properties efficiently and influences the temperature-sensitive swelling of the hydrogels but also has a minor effect on pH-sensitive swelling and promotes anticoagulation. MG-63 cells were used to test biocompatibility. Gelation occurred gradually through change in the elastic modulus as the release of calcium ions increased over time and caused ionic cross-linking, which promotes the elasticity of gel. In addition, the growth of MG-63 cells in the gel reflected nontoxicity. These results showed that this biocompatible scaffold has potential for application in bone materials.

A facile synthesis of high quality nanostructured CeO2 and Gd2O3-doped CeO2 solid electrolytes for improved electrochemical performance.

This study describes the use of a composite nitrate salt solution as a precursor to synthesize CeO2 and Gd2O3-doped CeO2 (GDC) nanoparticles (NPs) using an atmospheric pressure plasma jet (APPJ). The microstructures of CeO2 and GDC NPs were found to be cubical and spherical shaped nanocrystallites with average particle sizes of 10.5 and 6.7 nm, respectively. Reactive oxygen species, detected by optical emission spectroscopy (OES), are believed to be the major oxidative agents for the formation of oxide materials in the APPJ process. Based on the material characterization and OES observations, the study effectively demonstrated the feasibility of preparing well-crystallized GDC NPs by the APPJ system as well as the gas-to-particle mechanism. Notably, the Bader charge of CeO2 and Ce0.9Gd0.1O2 characterized by density function theory (DFT) simulation and AC impedance measurements shows that Gd helps in increasing the charge on Ce0.9Gd0.1O2 NPs, thus improving their conductivity and making them candidate materials for electrolytes in solid oxide fuel cells.

Effect of surfactant and budesonide on the pulmonary distribution of fluorescent dye in mice.

BACKGROUND: Surfactant is a useful vehicle for the intratracheal delivery of medicine to the distal lung. The aim of this study was to analyze the effect of intratracheal surfactant and budesonide instillation on the pulmonary distribution of fluorescent dye in mice. METHODS: Male athymic nude mice were assigned randomly as controls, fluorescent dye, fluorescent dye + surfactant (50 mg/kg), fluorescent dye + budesonide (0.25 mg/kg), and fluorescent dye + surfactant + budesonide groups. A total volume of 60 µL fluorescent solutions was intratracheally injected and followed by 60 µL of air. We photographed and measured fluorescence in the lungs, from the back, 15 minutes after intratracheal administration using an IVIS Xenogen imaging instrument. RESULTS: The fluorescent dye (1,1'-dioctadecyltetramethyl indotricarbocyanine iodide) was most strongly detected near the trachea and weakly detected in the lungs in mice administered with fluorescent solutions. Almost no fluorescence was seen in the lung region of control mice. Intratracheal administration of surfactant or budesonide increased fluorescent intensity compared with control mice. Combined administration of surfactant and budesonide further increased fluorescent intensity compared with mice given surfactant or budesonide alone. CONCLUSION: Surfactant and budesonide enhance the pulmonary distribution of fluorescent dye in mice.

A study of parameter setting and characterization of visible-light driven nitrogen-modified commercial TiO2 photocatalysts.

An optimal condition applied to the Taguchi method with an L(9) orthogonal array for preparing a visible-light driven nitrogen-modified TiO(2) (N-TiO(2)) photocatalyst by a simple hydrolysis method has been examined for material characteristics and a photodecolorization test of methyl blue (MB) under various visible light source (fluorescent and blue LED lamps) irradiations. Results of the material characterization showed that the absorption of prepared N-TiO(2) powder exhibited a significant extension into visible light regimes with an optical bandgap (Eg) of around 2.96 eV, which subsequently improved the visible-light photocatalytic activity of N-TiO(2) samples. The superior photocatalytic properties, the pseudo first-order reaction rate constants (k) and photodecolorization efficiency (η%) of a N-TiO(2) photocatalyst during the photodecolorization test of methyl blue (MB) under two different visible light irradiations were very evident compared to those for pure TiO(2). For photodecolorization of practical dyeing from the waste water from the dyeing and finishing industry, a higher photodecolorization efficiency of N-TiO(2) powder toward Direct blue-86 (DB-86) (Direct Fast Turquoise Blue GL) dye was also achieved.

Preparation of platinum- and silver-incorporated TiO2 coatings in thin-film photoreactor for the photocatalytic decomposition of o-cresol.

Platinum-incorporated TiO2 (Pt-TiO2) and silver-incorporated TiO2 (Ag-TiO2) coatings on sapphire tubes of a thin-film photoreactor were prepared using a photoreduction process. Results of X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) revealed that the Ag-TiO2 coatings consisted of a mixture of Ag2O, Ag and TiO2 particles, owing to the partial oxidization of silver particles on the TiO2 coatings, while the Pt-TiO2 coating contained a mixture of Pt and TiO2 particles. Diffuse reflectance UV-Vis spectra (DRS) showed that metal particles (Ag or Pt) incorporated into the TiO2 coatings promoted optical absorption in the visible region and made it possible for the coatings to be excited by visible light. Photoluminescence (PL) spectra showed that the PL intensity of the Pt-TiO2 coating was lower than that of the Ag-TiO2 and TiO2 coatings, indicating that the Pt-TiO2 coating had a higher efficiency of charge carrier trapping, immigration and transfer, which subsequently promoted the pseudo-first-order rate constants after the UV/TiO2 process. The Pt-TiO2 coatings for the photocatalytic decomposition of o-cresol under UV light irradiation corresponded to a higher pseudo-first-order rate constant (k) of 0.02 min(-1) when compared with the photocatalytic decomposition rates of pure TiO2 coatings (k = 0.0062 min(-1)) and Ag-TiO2 coatings (k = 0.01 min(-1)). The experimental results also indicated that the photodegradation rate of the Pt-TiO2 coating under visible light irradiation was significantly higher than the photodegradation rates of the Ag-TiO2 and pure TiO2 coatings.

Mineralization of reactive Black 5 in aqueous solution by ozone/H2O2 in the presence of a magnetic catalyst.

Particles are often too small to be separated from a reaction system and recycled, especially in wastewater treatment via a catalytic ozonation process. Thus, the objective of this study was to prepare a magnetic catalyst (SiO(2)/Fe(3)O(4)) that can be recycled by using an external magnetic field. The effects of the characteristics of the magnetic catalyst, pH values, catalyst dosage, and initial concentration of Reactive Black 5 (RB5) on mineralization efficiency of the magnetic catalyst/H(2)O(2)/O(3) process were also investigated. The mineralization efficiency of RB5 under various conditions followed the sequence: SiO(2)/Fe(3)O(4)/H(2)O(2)/O(3)>SiO(2)/Fe(3)O(4)/O(3)>Fe(3)O(4)/O(3) approximately H(2)O(2)/O(3)>O(3)>SiO(2)/Fe(3)O(4)/H(2)O(2). Given the results of our reuse and recovery experiments, the magnetic catalyst shows considerable promise for use in water treatment.

Reactions of Tp(NH[double bond, length as m-dash]CPh(2))(PPh(3))Ru-Cl with HC[triple bond, length as m-dash]CPh in the presence of H(2)O: insertion/hydration products.

The reaction of benzophenone imine complex (NH[double bond, length as m-dash]CPh(2))[Ru]Cl {[Ru] = Tp(PPh(3))Ru; Tp = HB(pz)(3), pz = pyrazolyl} with HC[triple bond, length as m-dash]CPh in the presence of H(2)O afforded the cis-alkynyl(vinylidene) complex [Ru](C[triple bond, length as m-dash]CPh)([double bond, length as m-dash]C[double bond, length as m-dash]CHPh) , as well as two alkenyl ketone regioisomers [Ru]C(CH(2)Ph)[double bond, length as m-dash]CHC(O)Ph and [Ru]C(Ph)[double bond, length as m-dash]CHC(O)CH(2)Ph . The combination of insertion and hydration process resulted in the unprecedented formation of the alkenyl ketone complexes.

Erratum: (Benzonitrile-κN)chlorido[hydrido-tris(pyrazol-1-yl-κN)borato](triphenyl-phosphine-κP)ruthenium(II) ethanol solvate. Corrigendum.

The author list in the paper by Tong, Hung, Wang, Lin & Lo [Acta Cryst. (2009), E65, m438] is corrected.[This corrects the article DOI: 10.1107/S1600536809010265.].

Effect of Pt/TiO2 characteristics on temporal behavior of o-cresol decomposition by visible light-induced photocatalysis.

Platinum deposited TiO(2) films were prepared on quartz substrates by dip-coating process for the photodecomposition of o-cresol. The characteristics of Pt/TiO(2) and the temporal behavior of o-cresol decomposition by Pt/TiO(2) photocatalysis under visible light irradiation were investigated. Platinum deposited on TiO(2) photocatalysts was characterized by Brunauer-Emmett-Teller (BET) surface area measurement, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), diffuse reflectance UV-Vis spectra (DRS) and photoluminescence (PL) emission spectra. The results indicated that the deposition of platinum on TiO(2) promoted the optical absorption in the visible region and made it possible to be excited by visible light. The decomposition rate of o-cresol under visible light irradiation from a fluorescent lamp was enhanced to noticeably extents for experiments conducted with Pt/TiO(2) containing platinum up to 0.50wt% platinum because of the presence of Ti(3+) resulted from the platinum deposited on the TiO(2) surface; and the formation of Schottky Barrier between platinum and TiO(2) preventing the recombination of electric holes and electrons. Specifically, the reaction rate of o-cresol photodegradation at pH 9 using the 0.50wt% Pt/TiO(2) was 4.8 times than that of using pure TiO(2). The intermediates identified by GC/MS spectroscopy during the photocatalytic oxidation of o-cresol. The proposed kinetic model could be adequately applied to describe the temporal behavior of the o-cresol decomposition with and without the dosage of Pt on TiO(2) in aqueous solution by UV/TiO(2) process.