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Sn/SnO2 nanocomposite of core-shell structure covered with multilayer graphene was synthesized by one step process of electrical wire explosion in liquid media. The synthesized Sn/SnO2 nanocomposites were characterized by various analyzers such as Raman, XRD, FESEM, FETEM, XPS and TGA. The electrochemical performance of the electrode has been investigated by galvanostatic cycling and cyclic voltammetry. FESEM and FETEM results showed that diameter of the Sn/SnO2 nanoparticles is around 10–50 nm and the thickness of the SnO2 shell is about 5–8 nm. The nanocomposite electrode showed a high specific capacity of 1270 mAhg−1 after 100 cycles. Furthermore, the nanocomposite exhibited high reversible capacity of around 650 mAhg−1 at the current density of 5000 mAg−1. These results indicated that multilayer graphene-encapsulated Sn/SnO2 nanocomposites are one of rational structural design to improve the electrochemical performance of Sn-based anode materials for LIBs.

Purpose: High fibular osteotomy (HFO) is a simple surgical technique to reduce pain and improve function in patients with osteoarthritis via fibular osteotomy. We report short-term results of HFO and mesenchymal cell induced chondrogenesis (MCIC) for the treatment of osteoarthritis of knee with varus deformity. Patients and methods: 45 symptomatic patients with 14 males and 31 females age ranging from 40 to 75 years were treated by HFO and MCIC. Main lesions involved medial compartment of knee and lateral compartment with normal to mild lesions of lateral meniscus and articular cartilage, amenable to treatment via partial meniscectomy or observation. Results: Knee injury and Osteoarthritis Outcome score and Lysholm showed a statistically significant increase and VAS, varus angle in X-ray showed a statistically significant decrease. A statistically significant difference between preoperative and postoperative scores was detected in male and female patients without any sexual differences. Conclusion: High fibular osteotomy and mesenchymal cell induced chondrogenesis can be considered as a good treatment option for medial compartment osteoarthritis of knee with varus deformity. Keywords: High fibular osteotomy, Osteoarthritis, Varus deformity, Knee, Mesenchymal cell induced chondrogenesis (MCIC)

Patterned Si film electrodes with trench structured Cu current collector were fabricated by using a facile approach. Ribbon-like Si films were embedded in the trench with 28 μm in trench height. The structural and electrochemical characteristics of the patterned electrodes were investigated after annealing at 200, 300 and 400 °C. For the as-deposited Si film, the Si film consisted of Si clusters at the bottom of trenches. With increasing annealing temperature, the Cu3Si phase was formed at 300 °C and came to the surface of the film electrode through boundaries of Si clusters, and then the coarsened Cu3Si phase covered the Si clusters at 400 °C. The best electrochemical performance was obtained from the 400 °C-annealed Si film electrode due to synergy effects of the formations of the Cu3Si layer and trench structure, which could suppress the Si volume change during repeated electrochemical reactions.

A hierarchically porous carbon nanofiber (HPCNF) material was prepared by a facile electrospinning method, with polyvinylpyrrolidone (PVP) as the carbon source and silica formed in-situ as the template. The carbon nanofibers showed a well-designed pore structure: centered macropores are surrounded by a denser cycle consisting of micro-/mesopores near the surface. Sulfur was encapsulated into the pores by solution penetration, followed by a melt diffusion method to generate a flexible sulfur/HPCNF (S/HPCNF) cloth as the binder-free cathode in lithium sulfur (Li-S) batteries. The HPCNF carbon with multi-scaled pores acts as an efficient host for large amounts of sulfur, and accommodates the associated volume expansion during electrochemical cycling. Moreover, the hierarchical architecture significantly reduces the escape of polysulfides during the cycling. The unique material allowed sulfur loading of 2.2–12.1 mg cm −2 , and exhibited a high sulfur utilization of more than 80% with high areal capacity of 11.3 mAh cm −2 , demonstrating that S/HPCNF is a promising cathode material for Li-S batteries of high energy density.

Low costs and high theoretical energy densities make room-temperature Na/S batteries attractive for large-scale applications. However, obtaining sulfur cathodes with high reversible capacities remains challenging. For sulfurized polyacrylonitrile (SPAN) cathode, we found the reaction mechanism between sodium and sulfur, and then developed a method to obtain high reversible capacity by electrochemical activation. During the first discharge (sodiation), one sodium per sulfur atom reacts irreversibly with the conjugated carbon backbone, which reduces the resistance of SPAN. Upon further sodiation, sodium reversibly reacts with free sulfur generated by cleaving C–S and S–S bonds in SPAN to form Na2S. After simple activation, i.e. further sodiation, 1.8 sodium atoms per sulfur atom, the reversible discharge capacity reaches 1502 mAh g−1-sulfur, similar to the theoretical capacity of Na2S, which is the highest value ever reported. After 100 cycles, the capacity remains at 1405 mAh g−1-sulfur; thus, the energy density of SPAN is 543 Wh kg−1, much higher than the theoretical value for lithium-ion batteries. The reported reaction mechanism and activation process provide new strategies for room-temperature Na/S batteries.

Micro carbon fibers (CFs) as a current collector were coated on sulfurized poly-acrylonitrile (SPAN) electrodes fabricated by using electrostatic flocking method. The alignment and flocking density of CFs and the electrochemical properties of SPAN electrodes were investigated with various flocking parameters of flocking distance, length of CF, and loading weight. A long flocking distance gave a sufficient space to rotate charged CFs and stand CFs on the surface of electrodes during flocking process. The flocking density was increased with a decrease of milling time and the increase of loading weight. The current collectors flocked with 12 h-milled carbon fibers (CFs) exhibited less weight than Al current collector. SPAN electrodes with CF current collector demonstrated better electrochemical performance than that with Al current collector. In particular, SPAN electrodes flocked with a loading weight of 0.3 g showed stable cycleability (76% of capacity retention until 100th cycle) and good rate capability (930 mAh/g_sulfur at 2.0 C-rate).

The contribution of chemical compositions in terms of carbon equivalent value (CEV) on impending crack propagation during weld bead bend tests (WBBTs) was studied with five different high-strength low-alloy steel plates that underwent different rolling processes. The test showed that cracks developed at the weld joint, easily passed through the coarse-grain heat-affected zone (CGHAZ), and finally were arrested within the heat-affected zone (HAZ). An apparent decrease in the average crack length, which consequently indicated improvement in crack arrestability, was found with decreasing CEV. In addition, the relatively fine microstructure in the HAZ of low-CEV steel plates helped in preventing the crack from further propagation. Special emphasis was placed on the empirical expectation of critical CEV above which WBBT might fail.

The structural and electrochemical properties of annealed Si film electrodes with titanium–nickel (TiNi) current collectors have been investigated to identify compounds and microstructures that improve electrochemical performances. The as-deposited Si/TiNi electrode consisted of amorphous Si (α–Si) and crystalline B2–TiNi alloy at room temperature. Only a thin oxide layer was formed at the interface, and any significant microstructural change was not found at 500 °C compared to the as-deposited electrode. The Ni atoms started to migrate from the TiNi alloy to the Si film at 600 °C, which resulted in the formation of a Ti-rich (Ti2Ni) layer at the interface. A large amount of Ni diffused into the Si film at 700 °C led to the formation of nickel silicide (NiSi2) particles being dispersed in the film. The Si/TiNi electrodes that were annealed at a temperature exceeding 600 °C showed improved electrochemical properties such as initial efficiency (~90%) and cycle performance (50% capacity retention after 300 cycles). The excellent electrochemical performance was achieved by enhancing the structural stability in annealed Si/TiNi electrodes.

A low-temperature oxidation-reduction process was used to modify the surface of a Cu current collector (foil) for a Si film electrode. The surfaces of the modified Cu foils were investigated under various oxidation-reduction conditions, and the electrochemical properties of Si film electrodes containing the surface modified foils were evaluated. Various nanostructures were found to have formed on the surface; for example, Cu(OH)2 needles, CuO flowers, and CuO plates formed on Cu-foil surfaces oxidized at 313 K for 1, 10, and 30 min, respectively. Furthermore, these nanostructures were transformed to coral-like Cu2O structures after reduction at 673 K. The amount of Cu2O and the surface roughness decreased on increasing reduction time. The Si film electrode containing a Cu foil reduced for 6 h showed the best electrochemical performance (83.5% of the initial efficiency and 74.8% of capacity retention) due to the small amount of Cu2O and the formation of coral-like structures.

The effects of solvents on the preparation of sulfur cathodes were investigated by fabricating binder-free sulfur electrode films using three different solvents: 1-methyl-2-pyrrolidinone (NMP), acetonitrile, and deionized water. These solvents are commonly employed to dissolve binders used to prepare sulfur cathodes for lithium–sulfur batteries. The sulfur electrode fabricated with NMP had a higher discharge capacity and longer cycle life than the ones fabricated with acetonitrile and deionized water. Better adhesion between the current collector and the sulfur electrode accounted for the improved capacity and cycle life of the battery. In addition, the stability of the electrode in the electrolyte was a result of the solubility of sulfur in the solvent. We thus concluded that the solvents used in the fabrication of sulfur electrodes had a positive influence on the electrochemical properties of Li–S batteries.

We prepared sulfur/active carbon composites via a simple solution-based process using the following commercial activated carbon-based materials: coal, coconut shells, and sawdust. Although elemental sulfur was not detected in any of the sulfur/activated carbon composites based on Thermogravimetric analysis, X-ray diffraction, and Raman spectroscopy, Energy-dispersive X-ray spectroscopy results confirmed its presence in the activated carbon. These results indicate that sulfur was successfully impregnated in the activated carbon and that all of the activated carbons acted as sulfur reservoirs. The sulfur/activated carbon composite cathode using coal exhibited the highest discharge capacity and best rate capability. The first discharge capacity at 1 C (1.672 A g−1) was 1240 mAh g−1, and a large reversible capacity of 567 mAh g−1 was observed at 10 C (16.72 A g−1).

Si film electrodes were fabricated on surface-modified Cu current collectors using an oxidation-reduction process. Flower-like nanostructures (FLNSs) with diameters of 2–3 μm and plate-like nanostructures (PLNSs) with lengths of 1 μm were formed on the Cu foil oxidized at 423 K for 0.5 h, but only the PLNSs remained after sonication. Reduction of the preoxidized Cu foil at 673 K resulted in the formation of plate-like and coral-like nanostructures on the Cu foils reduced for 1 and 3 h and a smooth surface without specific structures on the Cu foil reduced for 6 h. The best electrochemical properties in terms of the first columbic efficiency (85.4%) and the cycle performance (67.3% at 50 cycles) were obtained from the Si film electrode fabricated on the Cu foil that had been reduced for 3 h because the coral-like nanostructures on the Cu foil enhanced the adhesion of the Si film and improved the structural stability of the Si film electrode during the electrochemical reactions.

A phase-inversion technique is introduced to produce a porous Sn anode for sodium batteries, which can accommodate volume changes during sodiation and desodiation. The Sn electrode shows two plateaus with a capacity of 1066 mAh g−1 during the first sodiation and four flat plateaus with a charge capacity of 674 mAh g−1 at the first desodiation process. During 500 cycles, the Sn electrode shows reversible capacity more than 519 mAh g−1 with Coulombic efficiency of nearly 99%. The Sn electrode with a porous structure is a possible solution to the electrode degradation.

This study introduces a new flexible cathode that contains no binder, conductive additive and current collector, but instead consists solely of a sulfurized polyacrylonitrile nanofiber (SPAN) web which is prepared by a simple pyrolysis process with low cost raw materials. This not only exhibits good electrochemical properties, but also a high flexibility, rollability, and bendability to 180° without fracture. Its feasibility as a cathode for a low cost and flexible Na/S battery is subsequently evaluated on the basis that S, PAN, and Na are cheap materials. The SPAN web delivers a high first discharge capacity of 604 mAh g −1 – electrode (1473 mAh g −1 – sulfur) at 0.01 C based on sulfur content. In cycle performance at 0.1 C, a first discharge capacity of 342 mAh g −1 – electrode is obtained and remains over 266 mAh g −1 – electrode after 200 cycles along with the coulombic efficiency near 100% from the second cycle. In terms of rate capability, it is shown to be capable of delivering a capacity of as high as 71 mAh g −1 at 1 C. The reversible electrochemical reaction of the SPAN web with Na is related to a reversible bond between the C–S and S–S bonds of the SPAN web.

To realize a high-performance room temperature Na/S battery with an elemental sulfur cathode, it is important that sodium polysulfides stay within the cathode and that they have room enough to react freely. In this work, sodium polysulfides are confined to the cathode using a β″ alumina solid electrolyte separator and an optimal amount of tetraethylene glycol dimethyl ether (TEGDME) electrolyte. In addition, an activated carbon material, in the form of a sulfur/carbon (S/C) composite, with high surface area, porosity, and pore volume is employed in the cathode. The resulting Na/S battery shows a high first discharge capacity of 855 mAh g −1 and coulombic efficiency close to 100%, as well as stable cyclability, with a discharge capacity of 521 mAh g −1 at the 104th discharge.

One of the drawback of Tin (Sn) as anode material for Li-ion batteries (LIBs) is severe capacity fading due to pulverization of Sn particles during cycling. Many researchers have tried to solve this problem through various carbon coating on the surface of Sn particles. In this work, Sn/Carbon nanoparticles having various carbon coating thicknesses (0.0–7.0 nm) on the surface of Sn nanoparticles was fabricated by using pulsed wire explosion within various alcohol-based liquid media. The optimum carbon coating thickness needed to prevent crack of Sn nanoparticles was investigated. It was also investigated on when the cracks occurred during cycling using electrochemical analysis and acoustic emission signal analysis. It was found that around 95% of the crack is detected in the first cycling and the appropriate thickness of the carbon layer for the crack suppression is more than 5 nm.

Highlights: • The content of sulfur in activated carbon was controlled by solution process. • The sulfur electrode with low sulfur content shows the best performance. • The Li/S battery has capacity of 1360 mAh/g at 1 C and 702 mAh/g at 10 C. - Abstract: The content of sulfur in sulfur/activated carbon composite is controlled from 32.37 wt.% to 55.33 wt.% by a one-step solution-based process. When the sulfur content is limited to 41.21 wt.%, it can be loaded into the pores of an activated carbon matrix in a highly dispersed state. On the contrary, when the sulfur content is 55.33 wt.%, crystalline sulfur can be detected on the surface of the activated carbon matrix. The best electrochemical performance can be obtained for a sulfur electrode with the lowest sulfur content. The sulfur/activated carbon composite with 32.37 wt.% sulfur afforded the highest first discharge capacity of 1360 mAh g{sup −1} at 1 C rate and a large reversible capacity of 702 mAh g{sup −1} at 10 C (16.75 A/g)

Carbon-coated lithium iron phosphate (LiFePO4/C) with uniform carbon coating was synthesized by a mechanical activation method. Silicon negative electrode material was obtained in the form of thin films of amorphous silicon on a Cu foil substrate by vertical deposition technique. The electrochemical performance of the full cell, LiFePO4/C-Si, was tested with 1 M LiPF6 in EC/DMC at 0.5 and 1 C-rates. The cell exhibited an initial discharge capacity of 143.9 mAh g(-1) at 0.5 C-rate at room temperature. A reasonably good cycling performance under a high current density of 1 C-rate could be obtained with the full cell.

Nano Ni particle embedded Ni 3 S 2 powders (Ni-Ni 3 S 2 ) are prepared by means of melt spinning and 10 h-ball milling processes. The Ni particles with 10–20 nm size are dispersed over all the Ni 3 S 2 powders with 3.28 μm. Reversibility and rate capability of the Ni-Ni 3 S 2 electrode are investigated at various current densities from 0.1 C to 5 C by comparing with a conventional Ni 3 S 2 electrode. The Ni-Ni 3 S 2 electrode exhibits the remarkably improved reversibility of the redox reactions under high current density and 40% of discharge capacity retention at the current density of 2310 mA g −1 , corresponding to 5 C-rate. The improved electrochemical performances are mainly ascribed to ultra fine Ni particles that supplement the loss of Ni and promote the recovery of Ni 3 S 2 during charge process.

Highlights: • A highly porous carbon (HPC) with regular spherical morphology was synthesized. • Sulfur/HPC composites were prepared by melt–diffusion method. • Sulfur/HPC composites showed improved cyclablity and long-term cycle life. - Abstract: Sulfur composite material with a highly porous carbon sphere as the conducting container was prepared. The highly porous carbon sphere was easily synthesized with resorcinol–formaldehyde precursor as the carbon source. The morphology of the carbon was observed with field emission scanning electron microscope and transmission electron microscope, which showed a well-defined spherical shape. Brunauer–Emmett–Teller analysis indicated that it possesses a high specific surface area of 1563 m{sup 2} g{sup −1} and a total pore volume of 2.66 cm{sup 3} g{sup −1} with a bimodal pore size distribution, which allow high sulfur loading and easy transportation of lithium ions. Sulfur carbon composites with varied sulfur contents were prepared by melt–diffusion method and lithium sulfur cells with the sulfur composites showed improved cyclablity and long-term cycle life.

Sulfur composite was prepared by encapsulating sulfur into CMK-3 mesoporous carbon with different heating times and then used as the cathode material for lithium sulfur batteries. Thermal treatment at 300 °C plays an important role in the sulfur encapsulation process. With 20 h of heating time, a portion of sulfur remained on the surface of carbon, whereas with 60 h of heating time, sulfur is confined deeply in the small pores of carbon that cannot be fully exploited in the redox reaction, thus causing low capacity. The S/CMK-3 composite with thermal treatment for 40 h at 300 °C contained 51.3 wt.% sulfur and delivered a high initial capacity of 1375 mA h g−1 at 0.1 C. Moreover, it showed good capacity retention of 704 mA h g−1 at 0.1 C and 578 mA h g−1 at 2 C even after 100 cycles, which proves its potential as a cathode material for high capability lithium sulfur batteries.

Monolithic nickel sulfide electrodes were prepared using a facile synthesis method, sulfuration and annealing. As-prepared Ni3S2 electrodes were characterized by X-ray diffractometry and field emission scanning electron microscopy. Thermal stability was determined by thermal gravimetric analysis and differential scanning calorimetry. Electrochemical properties were measured by galvanostatic charge and discharge cycling for Na-ion batteries. Three kinds of Ni3S2 electrodes were prepared by varying the sulfuration time (5, 15 and 25 min). The electrochemical results indicated that the capacities increased with an increase in sulfuration time and the cycle performance was stable as a result of monolithic integration of nanostructured Ni3S2 on Ni plates, leading to low interfacial resistance.

Tin dioxide was investigated as an anode material for sodium-ion batteries. The Na/SnO2 cell delivered a first discharge capacity of 747 mAh/g, but the first charge capacity was 150 mAh/g. The irreversible capacity in the first cycle was examined through characterization by X-ray diffraction and scanning electron microscopy. X-ray diffraction analysis revealed that the SnO2 active material was not reduced fully to metallic Sn. Furrows and wrinkles were formed on the electrode surface owing to the volumetric expansion upon first discharge, which led to a deterioration of the electrode structure and a loss of electrical contact between the active materials. The analysis is summarized in the schematic drawing.

Pure α-NaMnO 2 cathode materials were prepared by solid-state reaction with Mn 2 O 3 and Na 2 CO 3 at 750 °C. Electrochemical properties of Na/α-NaMnO 2 battery was investigated with electrolytes as 1 M NaClO 4 EC/DEC and 1 M NaBF 4 TEGDME. First discharge capacity of Na/α-NaMnO 2 cell using 1 M NaClO 4 EC/DEC electrolyte and 1 M NaBF 4 TEGDME electrolyte was 146 mAh g −1 and 136 mAh g −1 discharge capacity for the first cycle at 0.2 C rate and 104 mAh g −1 97 mAh g −1 after 20 cycles, respectively. Na/α-NaMnO 2 battery with 1 M NaClO 4 EC/DEC electrolyte shows higher initial charge/discharge capacity than that using 1 M NaBF 4 TEGDME because of high ionic conductivity of electrolyte and low interfacial resistance between the electrolyte and electrode. However, Na/α-NaMnO 2 battery with 1 M NaBF 4 TEGDME electrolyte has better stability for the 20th cycle from coulombic efficiency result because of stability of interfacial resistance.

In this study, fine cathode materials Fe 0.8 Ni 0.2 S 2 and Fe 0.9 Ni 0.1 S 2 , with mean particle sizes of 3.39 μm and 2.79 μm, respectively, can be prepared simply through mechanical alloying (MA). The contents of nickel show a significant effect on the electrochemical behavior of the composites, as shown the charge/discharge capacity of 320/285 mAh/g is maintained for over 20 cycles for the Li/Fe 0.8 Ni 0.2 S 2 cell, higher than that for the Li/Fe 0.9 Ni 0.1 S 2 with 284/233 mAh/g when tested ranging from 0.8 to 2.4 V at 0.1 C. In addition, the electronic conductivity seemed also enhanced with high nickel doping content, leading to the improvement of the cycling stability of the FeS 2 based electrodes.

Background context Our previous in vivo study demonstrated that human nucleus pulposus chondrocytes (NPCs) in aging discs exhibited characteristic senescent features such as an increased senescence-associated β-galactosidase (SA-β-gal) expression, shortened telomere, and decreased telomerase activity. The replicative p53-p21-pRB pathway, rather than the stress-induced p16-pRB pathway, played a more important role in the senescence of NPCs in an in vivo condition, although there is a situation in which both the pathways can be activated simultaneously. However, the in vitro lifespan and senescence mechanisms of human NPCs remain unclear. Purpose To evaluate the underlying mechanisms of in vitro lifespan and in vitro senescence of the human NPCs and to verify whether the in vitro senescence mechanisms of the human NPC can represent the in vivo aging mechanisms of the cell. Study design/setting An in vitro study. Methods We serially cultivated human NPCs from patients of different ages (35, 42, 55, 66, and 76 years) until the cells reached the end of their in vitro lifespan. During each subcultivation, we calculated NPCs cumulative population doubling level (PDL) and examined senescence markers (SA-β-gal, telomere length, telomerase activity, and p53, p21, pRB, and p16 expressions). Results The cumulative PDLs of the NPCs from patients aged 35, 42 55, 66, and 76 years were 32, 29, 11, 9, and 11, respectively. The younger patients (35 and 42 years) had a higher mean of cumulative PDLs than the elderly patients did (55, 66, and 76 years; 30.5 vs. 10.3; p=.001). In addition, there was a significant, negative correlation between the cumulative PDLs and patient's age (r=−0.89; p=.04). With advancing culture passages, the NPCs irrespective of patient's age exhibited characteristic senescent features, such as an increase in SA-β-gal expression, shortening of telomeres, decrease in telomerase activity, and activation of both replicative p53-p21-pRB and stress-induced p16-pRB pathways. However, all the senescent features occurred at the earlier passages in elderly compared with younger patients. Conclusions The present study demonstrated that the human NPCs had a finite in vitro lifespan, which declined with host aging. The in vitro lifespan was determined by both replicative and stress-induced senescence mechanisms. The similarity in the in vitro senescent features with those apparent in the previous in vivo study suggests a possibility of the in vitro senescence mechanisms of the human NPC as a model of the in vivo aging mechanisms of the cell for future studies.

Background The aims of this study were to create a model of peritoneal carcinomatosis in patients with gastric cancer and to evaluates outcomes in patients with gastric cancer treated using surgery and hyperthermic intraperitoneal chemotherapy (HIPEC). Methods A single-institution cohort of patients with gastric cancer was analyzed according to the development of gastric cancer with peritoneal carcinomatosis (GCPC). Variables were evaluated using regression analysis. Kaplan-Meier analysis was used to evaluate outcomes after surgical resection, cytoreductive surgery, and HIPEC. Results Age ≤60 years and local tumor stage (T3/T4) were significantly associated with GCPC (odds ratio, 3.95 and 3.94, respectively). Thirty-six-month survival was 57% for patients without peritoneal disease and 39% for patients with GCPC. There was no significant trend of improved survival after surgical management or HIPEC. Conclusions Age ≤60 years and T3/T4 tumor stage are risk factors for GCPC. Intermediate-term survival of patients with GCPC treated with surgical resection or cytoreductive surgery and HIPEC was not improved, though future research should address the possible benefits of aggressive approaches to the treatment of GCRC.

The structural and electrochemical properties of Si film electrodes with Ni/Ti films on a Cu current collector (Si electrodes) were investigated after annealing in a temperature range of 400–600 °C. Metal-induced crystallization (MIC) and Kirkendall effects were simultaneously observed in the Si electrodes annealed above 450 °C for 2 h. The MIC effect led to the partial formation of strongly -oriented Si in the Si film, and the crystallinity of Si increased with increasing annealing temperature. The Kirkendall effect led to the diffusion of Cu and formed a Cu3Si layer on the surface of the Si film. The capacity of the Si electrodes decreased owing to the formation of the silicide and the efficiency was improved with increasing annealing temperature. A Si electrode annealed at 500 °C for 2 h exhibited good cycle performance with an activation region owing to the anisotropic lithiation during the initial cycles and the Cu3Si layers supporting the Si film.

Ni 3 S 2 powder has been fabricated by mechanical alloying Ni and S powders and the electrochemical properties of Na/Ni 3 S 2 cells fabricated from Na anodes and Ni 3 S 2 cathodes and 1 M sodium trifluoromethanesulfonate in tetraethyleneglycol dimethylether liquid electrolyte have been investigated. Upon discharging, the Ni 3 S 2 cathode transformed to amorphous Na 2 S, Ni and residual unconverted Ni 3 S 2 . On charging, the pristine structure of Ni 3 S 2 is fully recovered. The reversibility of this anode/cathode pair has been demonstrated and the discharge capacity loss of Na/Ni 3 S 2 cells has been investigated over 100 cycles. From TEM, EDS, XRD, and EIS results, the degradation mechanism appears to be the formation of nano-particles of Ni 3 S 2 and Na 2 S which become detached from the bulk cathode material causing the continuous increase in the interfacial resistance. Furthermore, many small cracks in Ni 3 S 2 cathode material are caused during repeated cycling and this is an additional phenomenon that leads to further degradation of the discharge capacity during cycling.

Prepared by the deposition of a solid electrode and electrolyte, all-solid-state batteries are a promising next generation battery system. Aerosol deposition (AD) offers many advantages compared to the conventional thin film deposition methods, including the deposition of a crystallized thin film with no heat treatment and a fast deposition rate. In this study, a LiFePO 4 /C composite thin film is directly fabricated using a LiFePO 4 /C composite raw powder. SEM and EDS results show the successful deposition of a LiFePO 4 /C composite thin film on a stainless steel substrate and X-ray diffraction patterns reveal that the as-deposited thin film has a crystalline structure, corresponding to the olivine phase, without any heat treatment. In a CV test, oxidation and reduction peaks appear at 3.51 and 3.36 V, corresponding closely to the peaks of bulk olivine LiFePO 4 . Furthermore, the profiles of the charge and discharge curves are similar to those of the bulk electrode and the discharge capacity is 31.1 μAh cm −2 μm −1 in the first cycle. After 20 cycles of 10.65 and 106.5 μA cm −2 μm −1 , the capacity is recovered to 30.7 μAh cm −2 μm −1 . Aerosol deposition can potentially be used in the fabrication of all-solid-state batteries.

LiCoO2 single-layer and LiCoO2/LiNiO2 multi-layer thin film electrodes were successfully fabricated by magnetron sputtering. Their microstructure and electrochemical properties were investigated. Once annealed, both films had the (0 0 3) preferred orientation to minimize the surface energy. The initial discharge capacity of the multi-layer thin film was approximately 53.1 μAh/cm2 μm, which was higher than that of the LiCoO2 single-layer thin film having similar thickness. The capacity retention of the multi-layer thin film was superior to that of the single-layer thin film. These findings indicate that the multi-layer thin film is a promising cathode material for the fabrication of high-performance thin film batteries.

The electrochemical and structural properties of Si thin film electrodes using a TiNi shape memory alloy as a current collector (substrate) are investigated with and without annealing. Annealed Si film electrodes exhibit an initial efficiency of 87% and a charge capacity retention (at the 50th cycle) of 85%. XRD results of the annealed Si film electrode during the charge–discharge process reveal the phase transformation (stress accommodation) of the TiNi substrate: cubic TiNi (initial) to monoclinic TiNi (after charge) and back to cubic TiNi (after discharge). SEM results of the annealed Si electrode show a remarkable reduction in structural damage of the Si film as compared to the as-deposited Si film electrode. The good electrochemical performances are ascribed to the high structural stability enhanced by both the post-annealing and stress accommodation of the TiNi substrate.

Discontinuous Si film electrodes with 400, 800, and 1700 μm discontinuous lines (break lines) were fabricated by a simple masking and etching process. The structural and electrochemical properties of continuous and discontinuous Si film electrodes were investigated by means of optical microscopy, field emission scanning electron microscopy, X-ray diffraction, and charge–discharge tests. Although all electrodes showed similar first-charge capacities in the range of 210–230 μAh/g, the discontinuous electrode exhibited improved coulombic efficiency and cyclability when compared to the continuous electrode. Up to 100 cycles, the discontinuous electrode with the shortest line distance of 400 μm demonstrated the highest efficiency (95.2%) and capacity retention (89%). Observation of the cycled Si film electrodes revealed that discontinuity enhanced the structural stability of the electrode during the charge–discharge process.

LiCoO2 thin films were fabricated on textured and annealed STS304 substrates by direct current magnetron sputtering method. The effects of the substrate texture on the structural and electrochemical properties of the LiCoO2 thin film deposited on both the substrates have been investigated. The crystal structures and surface morphologies of the deposited films were analyzed by X-ray diffractometry (XRD), Raman spectroscopy, and field emission scanning electron microscopy (FE-SEM). Based on the XRD analysis, the LiCoO2 thin film deposited on the textured substrate was found to exhibit (003) preferred orientation, while the film deposited on annealed substrate exhibited (104) preferred orientation. In addition, SEM analysis revealed that the film deposited on the textured substrate showed a smooth morphology. On the other hand, the film deposited on the annealed substrate exhibited a very rough surface morphology, which resulted in a higher surface area. Consequently, the initial discharge capacity of the film deposited on the annealed substrate was higher than that of the film deposited on the textured substrate. The film deposited on the textured substrate exhibited a good cyclic performance compared to the film deposited on the annealed substrate.

Background context Aeromonas hydrophila is a motile gram-negative non-sporeforming rod with facultative anaerobic metabolism. Except for gastrointestinal disease, skin and soft-tissue infections represent the second most common site of human Aeromonas infections. However, to our knowledge, A. hydrophila infection of the spine has not been reported to date. Purpose To report the first case of A. hydrophila spinal infection of the T7 vertebra after vertebroplasty. Study design Case report. Methods A 72-year-old man was transferred to our emergency department with chief complaints of severe midthoracic pain and triparesis. He had undergone vertebroplasty for a painful vertebral fracture at T7 5 weeks before transfer. Magnetic resonance imaging showed an infection of the T7 vertebroplasty and an extensive epidural abscess. The epidural abscess originating from the infected T7 vertebroplasty extended from the T8 to the C4 epidural space. Computed tomography demonstrated sparsely scattered gas in the epidural abscess, strongly suggestive of an anaerobic infection. Results Emergency multilevel laminectomies from C5 to T8 and a posterior instrumentation from T3 to T10 were performed. A. hydrophila was isolated from the blood cultures. The patient was treated with intravenous ampicillin/sulbactam. Posterior decompression and stabilization in combination with appropriate antibiotic treatment completely resolved the neurologic deficit and infection without the need for further anterior corpectomy of the infected T7 vertebroplasty. Conclusions This is the first reported case of spine infection caused by A. hydrophila. The infection developed after vertebroplasty for the management of a painful vertebral fracture. Triparesis occurred rapidly due to an extensive epidural abscess containing gas. Emergency decompression and stabilization in combination with appropriate antibiotic treatment achieved a successful clinical outcome.

We proposed new models of metamaterials (MMs) based on a flower-shaped structure (FSS), whose “meta-atoms” consist of two flower-shaped metallic parts separated by a dielectric layer. Like the non-symmetric MMs based on cut-wire-pairs or electric ring resonators, the symmetrical FSS demonstrates the negative permeability at GHz frequencies. Employing the results, we designed a symmetric negative-refractive-index MM [a symmetric combined structure (SCS)], which is composed of FSSs and cross continuous wires. The MM properties of the FSS and the SCS are presented numerically and experimentally.

The self-discharge of Zn anode material is identified as a main factor that can limit the energy density of alkaline Zn–air batteries. Al 2 O 3 has most positive effect on controlling the hydrogen evolution reaction accompanied by corroding Zn anode among various additives. The overpotential for hydrogen evolution is measured by potentio-dynamic polarization analysis. Al-oxide with high overpotential for hydrogen evolution reaction is uniformly coated on the surface of Zn powders via chemical solution process. The morphology and composition of the surface-treated and pristine Zn powders are characterized by SEM, EDS, XRD and XPS analyses. Aluminum is distributed homogeneously over the surface of modified Zn powders, indicating uniform coating of Al-oxide, and O1s and Al2 p spectra further identified surface coating layer to be the Al-oxide. The Al-oxide coating layer can prevent Zn from exposing to the KOH electrolyte, resulting in minimizing the side reactions within batteries. The 0.25 wt.% aluminum oxide coated Zn anode material provides discharging time of more than 10 h, while the pristine Zn anode delivers only 7 h at 25 mA cm −2 . Consequently, a surface-treated Zn electrode can reduce self-discharge which is induced by side reaction such as H 2 evolution, resulting in increasing discharge capacity.

New emerging large scale battery market has demanded low cost and high power or energy density materials. Sodium (Na) is a promising candidate for an anode material because of its low cost and natural abundance. Also molybdenum disulfide (MoS2) is an attractive cathode material with layered structure. In this study a Na/MoS2 cell was assembled so as to evaluate its electrochemical properties as a rechargeable battery. In the first discharge Na/MoS2 cell showed two characteristic plateaus at 0.93 V and 0.8 V. Galvanostatic charge/discharge cycle was carried out in different voltage ranges according to the discharge depths (0.85 V and 0.4 V). The electrochemical behaviors of Na/MoS2 cells at each discharge depth were analyzed through characterization of the crystallographic changes by employing ex situ X-ray diffractometry (XRD) and transmission electron microscopy (TEM). Finally, Na/MoS2 reaction mechanism was suggested.

Magnesium doped Li1−2xMgxFePO4/C (x = 0.00, 0.01, 0.03, 0.05) cathode materials were synthesized by sol–gel method, and the effect of magnesium doping as well as its content on the electrochemical properties for lithium batteries was also investigated. Their morphology was studied with field emission scanning electron microscope and Li1−2xMgxFePO4 materials showed the olivine phase without impurities. The thin carbon layer of Li1−2xMgxFePO4/C was confirmed by high resolution transmission electron microscopy. The magnesium doped Li1−2xMgxFePO4/C particles were smaller than those undoped. The Li1−2xMgxFePO4/C materials showed better cycling behavior than undoped LiFePO4, especially at high C-rate in which Li0.94Mg0.03FePO4/C composition exhibited the best electrochemical properties.

Gel polymer electrolytes (GPEs) were prepared with electrospun poly(vinylidene fluoride-co-hexafluoropropylene) [P(VdF-HFP)] nanofibrous membrane containing low molecular-weight polymer plasticizers, poly(ethylene glycol) dimethyl ether (PEGDME, Mw = 250 and 500). The fibers of electrospun membrane were stacked in layers to give fully interconnected pore structure with high porosity. The porous structure acted as a good host matrix to accommodate the polymer plasticizers. Thermogravimetric analysis (TGA) and field emission scanning electron microscope (FE-SEM) were used for thermal and physical characterizations, respectively. The GPEs exhibit high electrolyte uptake, high ionic conductivity, high anodic stability, and low interfacial resistance. Ionic conductivity and electrolyte uptake increased with the decrease in molecular weight of the polymer plasticizer. Prototype cells using electrospun P(VdF-HFP) nanofibrous GPEs with polymer plasticizers showed stable cyclic performances at different C-rates.

LiCoO 2 thin films were fabricated on Al substrate by direct current magnetron sputtering method. The effects of Ar/O 2 gas rates and annealing temperatures were investigated. Crystal structures and surface morphologies of the deposited films were investigated by X-ray diffraction, Raman scattering spectroscopy and field emission scanning electron microscopy. The as-deposited LiCoO 2 thin films exhibited amorphous structure. The crystallization starts at the annealing temperature over 400 °C. However, the annealed films have the partially disordered structure without completely ordered crystalline structure even at 600 °C annealing. The electrochemical properties of the LiCoO 2 films were investigated by the charge–discharge and cycle measurements. The 500 °C annealing film has the highest capacity retention rate of 78.2% at 100th cycles.

We investigated the dependence of reflectance and absorbance of a metamaterial structure (consisting of unit cells with two metallic parts, an electric ring resonator (ERR) at the front and a cut-wire bar at the back, separated by a dielectric layer) on gap ‘g’ of the structure at GHz frequencies. Our simulation results have shown that, by increasing the gap, the maximum absorbance and the minimum reflectance were obtained to be 94.42 and 0.74%, respectively, at 12.3 GHz. It was significant that the geometry of ERR was changed as an I-shape to observe a narrow-band peak of the perfect-absorber effect, whose absorbance was enhanced to be greater than 99.5% at 13.5 GHz by using a multilayer model for the simplified absorber structure.

The aim of this study is to investigate the capability of an apoA-I mimetic with multiple amphipathic helices to form HDL-like particles in vitro and in vivo. To generate multivalent helices and to track the peptide mimetic, we have constructed a peptibody by fusing two tandem repeats of 4F peptide to the C terminus of a murine IgG Fc fragment. The resultant peptidbody, mFc-2X4F, dose-dependently promoted cholesterol efflux in vitro, and the efflux potency was superior to monomeric 4F peptide. Like apoA-I, mFc-2X4F stabilized ABCA1 in J774A.1 and THP1 cells. The peptibody formed larger HDL particles when incubated with cultured cells compared with those by apoA-I. Interestingly, when administered to mice, mFc-2X4F increased both pre-β and α-1 HDL subfractions. The lipid-bound mFc-2X4F was mostly in the α-1 migrating subfraction. Most importantly, mFc-2X4F and apoA-I were found to coexist in the same HDL particles formed in vivo. These data suggest that the apoA-I mimetic peptibody is capable of mimicking apoA-I to generate HDL particles. The peptibody and apoA-I may work cooperatively to generate larger HDL particles in vivo, either at the cholesterol efflux stage and/or via fusion of HDL particles that were generated by the peptibody and apoA-I individually.

Patterned Si films (electrodes) on flat and rough substrates were fabricated by masking with an expanded metal foil during film deposition. Their electrochemical properties and structural stability during charge-discharge process were examined and compared with each other. The patterned Si film fabricated on the rough substrate (rough electrode) exhibited the improved cycleability (91% of capacity retention after 100 cycles) and the enhanced structural stability compared to the patterned Si film fabricated on the flat substrate (flat electrode). After 50 cycles, some cracks were generated at Si tile in the flat electrode, whereas any structural damages were not observed at the rough electrode. The good electrochemical performance of the rough electrode was attributed to the space between Si tiles and the enhanced structural stability of electrode.

A ZnO film was deposited, and the magnetic and the magnetoresistive ( MR ) properties were studied. The MR measurements reveal negative MR at 80, 50, 20, 10 and 6 K, which is supposed to be induced by the weak-localization effect, based on a logarithmic dependence of the electrical conductivity on temperature. When temperature was reduced to be 2 K, a positive MR was observed. We suggest that it is related to the spin splitting induced by exchange interaction between itinerant electrons and vacancy defects in ZnO. Through the magnetic measurement, it is found that ZnO shows ferromagnetism. It is suggested that the observed ferromagnetism is correlated with the exchange interaction.

For a Na/Ni 3 S 2 cell operating at room temperature, three kinds of tetra (ethylene glycol) dimethyl ether (TEGDME) electrolytes, containing sodium trifluoromethane sulfonate (NaCF 3 SO 3 ), sodium hexafluorophosphate (NaPF 6 ), and sodium perchlorate (NaClO 4 ) salts, respectively, were prepared. Na/Ni 3 S 2 cells with 1 M NaCF 3 SO 3 in TEGDME showed a discharge plateau potential of 0.85 V and a first discharge capacity of 448 mAh/g. The discharge capacity decreased to 250 mAh/g after 40 cycles, which represented the best cycling performance among the three electrolytes.

We have grown high quality GaN layers on (111)-oriented silicon substrate using a two-step growth method and fabricated high-performance normally-off n-channel GaN Schottky-barrier MOSFET (SB-MOSFET). Indium-tin-oxide (ITO) was used as Schottky-barrier contact for source and drain (S/D) because the work function of ITO is close to the electron affinity of GaN. Due to enhanced crystalline quality and reduced surface roughness of GaN layer grown by two-step process, the fabricated device exhibited much improved performances: sufficiently high threshold voltage of 3.75V, subthreshold slope of 171mV/dec, low specific on-resistance of 9.98m@Wcm^2, and very high field-effect mobility of 271cm^2/Vs. This is the highest mobility value among the GaN MOSFETs ever reported so far.

The first discharge curve of a sodium–sulfur cell using a tetra ethylene glycol dimethyl ether liquid electrolyte at room temperature shows two different regions: a sloping region and a plateau region of 1.66 V. The first discharge capacity is 538 mAh g −1 sulfur and then decreases with repeated charge–discharge cycling to give 240 mAh g −1 after ten cycles. Elemental sulfur of the cathode changes to sodium polysulfides Na 2 S 2 and Na 2 S 3 , during full discharge. The sodium polysulfides, however, do not reduce completely to elemental sulfur after full charging. In summary, the mechanism of the battery with liquid electrolyte is 2Na + n S → Na 2 S n (4 > n ≥ 2) on discharge and Na 2 S n (4 > n ≥ 2) → x (2Na + n S) + (1 − x )Na 2 S n (5 > n > 2) on charge.

In order to investigate the role of iron additive in the Ni3S2 electrode, the Ni3S2 electrode was prepared by addition of iron. The discharge properties of Na/Ni3S2 cells using 1 M NaCF3SO3 in tetra(ethylene glycol)dimethyl ether liquid electrolyte were investigated at room temperature. The Na/Ni3S2 cell had an initial discharge capacity of 400 mAh g−1 with a plateau potential at 0.84 V versus Na/Na+. The discharge capacity decreased to 255 mAh g−1 after 15 cycles. Iron additive in Ni3S2 electrode played a role as a conductive agent and did not form iron sulfide during charging.

In view of the safety concerns and the requirements of high energy density lithium batteries, the room temperature ionic liquids (RTILs) are being investigated as suitable candidates to substitute organic electrolytes in polymer electrolytes. In this article, we report synthesis, characterization, and electrochemical properties of nanocomposite polymer electrolytes (NCPEs) comprising of a RTIL [ n -butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMITFSI)] and nano-sized ceramic fillers (SiO 2 , Al 2 O 3 or BaTiO 3 ) hosted in electrospun poly(vinylidene fluoride- co -hexafluoropropylene) [P(VdF-HFP)] membranes. The addition of BMITFSI and ceramic fillers in polymer electrolytes results in high ionic conductivity at room temperature. The cells prepared with BMITFSI and different NCPEs show good interfacial stability and oxidation stability at >5.5 V with the highest value of 6.0 V for the NCPE incorporating BaTiO 3 . The cell with the NCPE containing BaTiO 3 delivers high initial discharge capacity of 165.8 mA h g −1 , which corresponds to 97.5% utilization of active material under the test conditions, and showed the least % capacity fade after prolonged cycling.