In Situ Formed Ag-Li Intermetallic Layer for Stable Cycling of All-Solid-State Lithium Batteries.

With the timely advent of the electric vehicle era, where battery stability has emerged as a major issue, all-solid-state batteries (ASSBs) have attracted significant attention as the game changer owing to their high stability. However, despite the introduction of a densely packed solid electrolyte (SE) layer, when Li is used to increase the energy density of the cell, the short-circuit problem caused by Li protrusion is unavoidable. Furthermore, most strategies to control nonuniform Li growth are so complicated that they hinder the practical application of ASSBs. To overcome these limitations, this study proposes an Ag-Li alloy anode via mass-producible roll pressing method. Unlike previous studies reporting solid-solution-based metal alloys containing a small amount of lithiophilic Ag, the in situ formed and Ag-enriched Ag-Li intermetallic layer mitigates uneven Li deposition and maintains a stable SE/Ag-Li interface, facilitating reversible Li operation. Contrary to Li cells showing frequent initial short-circuit, the cell incorporating the Ag-Li anode exhibits a better capacity retention of 94.3% for 140 cycles, as well as stable cycling even under 12 C. Through a facile approach enabling the fabrication of a large-area anode with controllable Li growth, this study provides practical insight for developing ASSBs with stable cyclabilities.

A Novel Strategy to Overcome the Hurdle for Commercial All-Solid-State Batteries via Low-Cost Synthesis of Sulfide Solid Electrolytes.

Unlike commercial lithium-ion batteries, the high cost and low ionic conductivity of solid electrolytes (SEs) continues to be a big hurdle in commercially available all-solid-state batteries (ASSBs). Rather than the conventional dry-process and high-energy ball milling processes, the productive solution synthesis of bulk-type SEs is the most crucial issue in the successful application of high-energy-density ASSBs. In this study, the way is paved to overcome the hurdle for commercial lithium phosphorus sulfide chloride (LPSCl) SEs via a readily processable bulk-type solution-based synthesis without acquiring any high-energy ball-milling processes. By incorporating an elemental sulfur additive during the preparation process, Li2 S and S form a polysulfide, and P2 S5 is induced to react readily to provide LPSCl with excellent ion conductivity as high as 1.8 mS cm-1 . Surprisingly, the purity of bulk type precursors does not affect the final composition and ionic conductivity of sulfide electrolytes, which show the same electrochemical characteristics of ASSB cells with a high discharge capacity of 185.6 mA h g-1 . The study offers a promising strategy for saving the production cost of sulfide SEs, possibly up to 92%, and their commercial ASSBs are expected to be achieving a competitive cost per energy density of ≈0.46 $ W-1 .

Vertically Aligned Binder-Free TiO2 Nanotube Arrays Doped with Fe, S and Fe-S for Li-ion Batteries.

Vertically aligned Fe, S, and Fe-S doped anatase TiO2 nanotube arrays are prepared by an electrochemical anodization process using an organic electrolyte in which lactic acid is added as an additive. In the electrolyte, highly ordered TiO2 nanotube layers with greater thickness of 12 µm, inner diameter of approx. 90 nm and outer diameter of approx. 170 nm are successfully obtained. Doping of Fe, S, and Fe-S via simple wet impregnation method substituted Ti and O sites with Fe and S, which leads to enhance the rate performance at high discharge C-rates. Discharge capacities of TiO2 tubes increased from 0.13 mAh cm-2(bare) to 0.28 mAh cm-2 for Fe-S doped TiO2 at 0.5 C after 100 cycles with exceptional capacity retention of 85 % after 100 cycles. Owing to the enhancement of thermodynamic and kinetic properties by doping of Fe-S, Li-diffusion increased resulting in remarkable discharge capacities of 0.27 mAh cm-2 and 0.16 mAh cm-2 at 10 C, and 30 C, respectively.

Facile fabrication of solution-processed solid-electrolytes for high-energy-density all-solid-state-batteries by enhanced interfacial contact.

Instead of commercial lithium-ion batteries (LIBs) using organic liquid electrolytes, all-solid-state lithium-ion batteries (ASSBs) employing solid electrolytes (SEs) are promising for applications in high-energy-density power applications and electric vehicles due to their potential for improving safety and achieving high capacity. Although remarkable progress in SEs has been achieved and has resulted in high ionic conductivity, which now reaches values comparable to those of liquid electrolytes, the typical use of a slurry process for the fabrication of conventional ASSBs inevitably causes harmful reactions between sulfide materials and polar solvents. Here, we studied the efficient infiltration process of SE slurry into conventional composite LIB electrodes (NCM622) for achieving high-energy-density ASSBs via a scalable solution-based fabrication process. Two methods are proposed to ensure that SE materials are evenly distributed and sufficiently infiltrated into the porous structures of LIB electrodes. The LPSCl SE solutions were effectively infiltrated into the electrodes at higher processing temperatures and the temperature was subsequently optimized at above the boiling point of the ethanol solvent due to the dynamic motion of SE molecules via a convective flow during solvent vaporization. Moreover, the porous LIB composite electrodes with a mixture of active materials of different particle sizes formed and filled capillary pores resulting in a high electrode density. The LPSCl SE-infiltrated NCM622 electrodes that used this strategy could remarkably improve the initial discharge capacity of ASSBs to as high as 177 mAh/g. These ASSBs also showed excellent performance even at high loading values (about 17 mg/cm2), making them competitive with LIBs using conventional liquid electrolytes.

Graphitic Hollow Nanocarbon as a Promising Conducting Agent for Solid-State Lithium Batteries.

All-solid-state batteries (ASSBs) have lately received enormous attention for electric vehicle applications because of their exceptional stability by engaging all-solidified cell components. However, there are many formidable hurdles such as low ionic conductivity, interface instability, and difficulty in the manufacturing process, for its practical use. Recently, carbon, one of the representative conducting agents, turns out to largely participate in side reactions with the solid electrolyte, which finally leads to the formation of insulating side products at the interface. Although the battery community mentioned that parasitic reactions are presumably attributed to carbon itself or the generation of electronic conducting paths lowering the kinetic barrier for reactions, the underlying origin for such reactions as well as appropriate solutions have not been provided yet. In this study, for the first time, it is verified that the functional group on carbon is an origin for causing negative effects on interfacial stability and a graphitized hollow nanocarbon as a promising solution for improving-electrochemical performance is introduced. This work offers an invaluable lesson that a relatively minor part, such as a conducting agent, in ASSBs sometimes gives more positive impact on improving electrochemical performance than huge efforts for resolving other parts.

Enhanced osteogenic differentiation of human mesenchymal stem cells on Ti surfaces with electrochemical nanopattern formation.

Titanium (Ti) and its alloys are mainly used for dental and orthopedic applications due to their excellent biocompatibility and mechanical properties. However, their intrinsic bioinertness often quotes as a common complaint for biomedical applications. Herein, we produced nanopattern Ti surfaces with 10 nm nanopores in 120 nm dimples by electrochemical nanopattern formation (ENF), and evaluated the osteogenic differentiation of human mesenchymal stem cells (hMSCs) on the nanopattern Ti surfaces. The ENF surfaces were obtained by removing the TiO2 nanotube (NT) layers prepared by an anodization process. To determine the in vitro effects of the ENF surface, cell proliferation assay, alkaline phosphatase activity assay, alizarin red staining, western blotting, and immunocytochemistry were performed. Atomic force microscopy and scanning electron microscopy analysis show that the ENF surface has an ultrafine surface roughness with highly aligned nanoporous morphology. hMSCs on ENF surfaces exhibit increased proliferation and enhanced osteogenic differentiation as compared to the ordered TiO2 nanotubular and compact TiO2 surfaces. Surface modification with the ENF process is a promising technique for fabricating osteointegrative implant materials with a highly bioactive, rigid and purified nano surfaces.

LiI-Doped Sulfide Solid Electrolyte: Enabling a High-Capacity Slurry-Cast Electrode by Low-Temperature Post-Sintering for Practical All-Solid-State Lithium Batteries.

All-solid-state lithium batteries (ASSLBs) based on sulfide solid electrolytes (SEs) have received great attention because of the high ionic conductivity of the SEs, intrinsic thermal safety, and higher energy density achievable with a Li metal anode. However, studies on practical slurry-cast composite electrodes show an extremely limited battery performance than the binder-free pelletized electrodes because of the poor interfacial robustness between the active materials and SEs by the presence of a polymeric binder. Here, we employ a low-temperature post-sintering process for the slurry-cast composite electrodes in order to overcome the binder-induced detrimental effects on the electrochemical performance. The LiI-doped Li3PS4 SEs are chosen because the addition of iodine not only improves the Li-ion conductivity and Li metal compatibility but also lowers the glass-transition and crystallization temperatures. Low-temperature post-sintering of composite cathodes consisting of a LiNi0.6Co0.2Mn0.2O2-active material, LiI-doped Li3PS4 SE, polymeric binder, and conducting agent shows a significantly improved electrochemical performance as compared to a conventional slurry-cast electrode containing pre-annealed SEs. Detailed analyses by electrochemical impedance spectroscopy and galvanostatic intermittent titration technique confirm that post-sintering effectively reduces the interfacial resistance and enhances the chemomechanical robustness at solid-solid interfaces, which enables the development of practical slurry-cast ASSLBs with sulfide SEs.

Production of Oxidation-Resistant Cu-Based Nanoparticles by Wire Explosion.

The low performance or high cost of commercially available conductive inks limits the advancement of printed electronics. This article studies the explosion of metal wires in aqueous solutions as a simple, low-cost, and environmentally friendly method to prepare metallic nanoparticles consisting of Cu and Cu alloys for use in affordable, highly conductive inks. Addition of 0.2 M ascorbic acid to an aqueous explosion medium prevented the formation of Cu2O shells around Cu nanoparticles, and allowed for the printing of conductive lines directly from these nanoparticles with no post-treatment. Cu alloy nanoparticles were generated from metal wires that were alloyed as purchased, or from two wires of different metals that were twisted together. Cu nanoparticles alloyed with 1% Sn, 5% Ag, 5% Ni and 30% Ni had electrical conductivities similar to Cu but unlike Cu, remained conductive after 24 hrs at 85 °C and 85% RH.

Real-time visualization of diffusion-controlled nanowire growth in solution.

This Letter shows that copper nanowires grow through the diffusion-controlled reduction of dihydroxycopper(I), Cu(OH)2(-). A combination of potentiostatic coulometry, UV-visible spectroscopy, and thermodynamic calculations was used to determine the species adding to growing Cu nanowires is Cu(OH)2(-). Cyclic voltammetry was then used to measure the diffusion coefficient of Cu(OH)2(-) in the reaction solution. Given the diameter of a Cu nanowire and the diffusion coefficient of Cu(OH)2(-), we calculated the dependence of the diffusion-limited growth rate on the concentration of copper ions to be 26 nm s(-1) mM(-1). Independent measurements of the nanowire growth rate with dark-field optical microscopy yielded 24 nm s(-1) mM(-1) for the growth rate dependence on the concentration of copper. Dependence of the nanowire growth rate on temperature yielded a low activation energy of 11.5 kJ mol(-1), consistent with diffusion-limited growth.

The role of cuprous oxide seeds in the one-pot and seeded syntheses of copper nanowires.

This paper demonstrates that Cu2O nanoparticles form in the early stages of a solution-phase synthesis of copper nanowires, and aggregate to form the seeds from which copper nanowires grow. Removal of ethylenediamine from the synthesis leads to the rapid formation of Cu2O octahedra. These octahedra are introduced as seeds in the same copper nanowire synthesis to improve the yield of copper nanowires from 12% to >55%, and to enable independent control over the length of the nanowires. Transparent conducting films are made from nanowires with different lengths to examine the effect of nanowire aspect ratio on the film performance.

A rapid synthesis of high aspect ratio copper nanowires for high-performance transparent conducting films.

This communication presents a way to produce copper nanowires with aspect ratios as high as 5700 in 30 min, and describes the growth processes responsible for their formation. These nanowires were used to make transparent conducting films with a transmittance >95% at a sheet resistance <100 Ω sq(-1).

Extended self-ordering regime in hard anodization and its application to make asymmetric AAO membranes for large pitch-distance nanostructures.

We report here a fast and reliable hard anodization process to make asymmetric anodic aluminum oxide (AAO) membranes which can serve as a template for large pitch-distance nanostructures. In order to make larger pitch distances possible, the common burning failure associated with the high current density during the conventional constant voltage hard anodization, especially at a voltage higher than a known limit, i.e., 155 V for oxalic acid, was effectively suppressed by using a burning-protective agent. A new self-ordering regime beyond the voltage limit was observed with a different voltage-interpore distance relationship of 2.2 nm V(-1) compared to the reported 2.0 nm V(-1) for hard anodization. Combining a sulfuric acid mild anodization with this new regime of hard anodization, we further demonstrate a scalable process to make an asymmetric membrane with size up to ~47 mm in diameter and ~60 µm in thickness. This free-standing membrane can be used as a template for novel nanopatterned structures such as arrays of quantum dots, nanowires or nanotubes with diameters of a few tens of nanometers and pitch distance of over 400 nm.

Pathogenesis and Chronologic Localization of the Human Influenza A (H1N1) Virus in Cotton Rats.

OBJECTIVES: We aimed to evaluate the pathogenesis and chronologic localization of human influenza A (H1N1) virus in experimentally infected cotton rats. METHODS: The animals were intranasally inoculated with 10(7) plaque-forming units of A/Solomon Islands/3/2006 (H1N1) influenza virus and evaluated for pathogenicity for a period of 28 days. Virus replication kinetics and pathological properties were assessed chronologically. Acute antiviral responses were evaluated by mean of real-time polymerase chain reaction. RESULTS: Cotton rats infected with A/Solomon Islands/3/2006 virus lost weight until 6 days post-inoculation (DPI) and showed decreased activity until 3 DPI. At necropsy, focal areas of redness and consolidation of lungs were evident at 1, 2, and 3 DPI. Lung histopathology showed moderate to severe interstitial pneumonia, alveolitis and bronchiolitis. Influenza A specific viral protein was detected in bronchiolar epithelial cells, alveolar septa and pneumocytes. Influenza viruses were recovered from the lungs during the early period of infection and the titer peaked at 1 DPI. Viral proteins were detected from 4 hours to 6 hours DPI. These trends correlate with the up-regulation of mRNA expression of the IFN-α, Mx1, and Mx2 genes that play critical roles in the anti-influenza response at the early stage of infection. CONCLUSION: Our results provide evidence that supports the use of cotton rats for the study of influenza virus pathogenesis and the immune response.

Replication and pathogenesis of the pandemic (H1N1) 2009 influenza virus in mammalian models.

This study aimed to characterize the replication and pathogenic properties of a Korean pandemic (H1N1) 2009 influenza virus isolate in ferrets and mice. Ferrets infected with A/Korea/01/2009 (H1N1) virus showed mild clinical signs. The virus replicated well in lungs and slightly in brains with no replication in any other organs. Severe bronchopneumonia and thickening of alveolar walls were detected in the lungs. Viral antigens were detected in the bronchiolar epithelial cells, in peribronchial glands with severe peribronchitis and in cells present in the alveoli. A/Korea/01/2009 (H1N1) virus-infected mice showed weight loss and pathological lung lesions including perivascular cuffing, interstitial pneumonia and alveolitis. The virus replicated highly in the lungs and slightly in the nasal tissues. Viral antigens were detected in bronchiolar epithelial cells, pneumocytes and interstitial macrophages. However, seasonal H1N1 influenza virus did not replicate in the lungs of ferrets, and viral antigens were not detected. Thus, this Korean pandemic (H1N1) 2009 isolate infected the lungs of ferrets and mice successfully and caused more pathological lesions than did the seasonal influenza virus.

Toxicity and clearance of intratracheally administered multiwalled carbon nanotubes from murine lung.

Carbon nanotubes (CNT) are known to have widespread industrial applications; however, several reports indicated that these compounds may be associated with adverse effects in humans. In this study, multiwalled carbon nanotubes were administered to murine lungs intratracheally to determine whether acute and chronic pulmonary toxicity occurred. In particular, pristine multiwalled carbon nanotubes (PMWCNT) and acid-treated multiwalled carbon nanotubes (TMWCNT) were used in this study. In broncheoalveolar lavage fluid (BALF) cell analysis, PMWCNT induced more severe acute inflammatory cell recruitment than TMWCNT. Histopathologically, both PMWCNT and TMWCNT induced multifocal inflammatory granulomas in a dose-dependent manner. The observed granulomas were reversible, with TMWCNT-induced granulomas diminishing faster than PMWCNT-induced granulomas. Although the area of granuloma reduced with time, hyperplasia and dysplastic characteristics such as mitotic figures, anisokaryosis, and anisocytosis were still observed. These findings demonstrate that MWCNT induces granulomatous inflammation, and the duration and pattern of inflammation seem to vary depending upon the types of MWCNT to which mice are exposed. Therefore, toxicity studies on various types of CNT are needed as the responsiveness to these compounds differs.

Low dietary inorganic phosphate stimulates lung tumorigenesis through altering protein translation and cell cycle in K-ras(LA1) mice.

Recent surveys indicate that Pi intake has increased steadily as Pi-containing foods have increased. Our previous study demonstrated that high dietary Pi strongly stimulated lung tumorigeneis. In order to answer the issue whether low Pi may be chemopreventive, we examined the effects of low Pi on lung cancer. Eighteen 5-wk-old male K-ras(LA1) lung cancer model mice were randomly allocated to 2 groups. One group was fed a normal diet (0.5% Pi) and other group was fed low Pi (0.1% Pi) diet for 4 wk. Lung cancer development was evaluated by histopathological examination, Western blot, kinase assay, and immunohistochemistry. Low Pi increased the expression of sodium-dependent phosphate co-transporter 2b, and activated Akt signal with decreased PTEN expression in the lungs of K-ras(LA1) mice. Low Pi increased the Akt/mTOR-mediated protein translation through upregulating the phosphorylation of p70S6K and 4E-BP1. In addition, low Pi stimulated cell cycling as evidenced by altered cell cycle regulators such as cyclin D1 and D3. Finally, low Pi increased lung tumorigenesis in K-ras(LA1) mice compared to the normal diet group. Our results clearly demonstrated that low Pi also promoted lung tumorigenesis, thus suggesting that an appropriate intake of dietary Pi may be critical for lung cancer prevention as well as treatment.

Development of in situ hybridization for the detection of Mycoplasma hyorhinis in formalin-fixed paraffin-embedded tissues from naturally infected pigs with polyserositis.

The aim of this study was to develop in situ hybridization for detection of Mycoplasma hyorhinis in formalin-fixed, paraffin-wax-embedded tissues from pigs with polyserositis. M. hyorhinis was isolated from the spleen (2 pigs) and pericardium (1 pig). M. hyorhinis DNA was detected 16 out of 20 pigs with polyserositis. In situ hybridization produced a distinct positive signal for the M. hyorhinis p37 gene in inflammatory cells in the polyserositis. In situ hybridization developed in the present study present diagnostic tools capable of detection of M. hyorhinis in formalin-fixed, paraffin-wax-embedded tissues from the naturally infected pigs.

Development of in situ hybridization assay that differentiates between two genotypes of Porcine circovirus-2 in formalin-fixed, paraffin-embedded tissues.

The aim of the current study was to develop a nonradioactive in situ hybridization assay that can differentiate between genotypes 2a and 2b of Porcine circovirus-2 (PCV-2) in formalin-fixed, paraffin-embedded lymph node tissues from pigs with postweaning multisystemic wasting syndrome. Two different digoxigenin-labeled oligonucleotide probes were designed from the PCV-2 open reading frame 2 sequences. The PCV-2a-specific probe did not hybridize with formalin-fixed, paraffin-embedded lymph nodes from naturally PCV-2b-infected pigs and vice versa. Both PCV-2a-specific and PCV-2b-specific probes gave consistent negative signals in lymph nodes from naturally PCV-1-infected pigs. The in situ hybridization assay described in the present study represents a diagnostic tool that can differentiate between the 2 genotypes of PCV-2.

Colostral transmission of porcine circovirus 2 (PCV-2): reproduction of post-weaning multisystemic wasting syndrome in pigs fed milk from PCV-2-infected sows with post-natal porcine parvovirus infection or immunostimulation.

Post-weaning multisystemic wasting syndrome (PMWS) was reproduced in pigs fed colostrum and milk from porcine circovirus 2 (PCV-2)-infected sows and infected post-natally with porcine parvovirus (PPV) or immunostimulated. Pregnant sows were inoculated intranasally with either PCV-2 (n=5) or PCV-2-free PK-15 cell lysates (control, n=10) 3 weeks before the expected farrowing date. Newborn piglets from five of the control sows were introduced to PCV-2-infected sows (n=6 for each sow) and allowed to feed on the colostrum for 12 h and then given 15 ml milk five times a day for 7 days. Newborn piglets from the other five control sows were fed colostrum and milk from their own sows. After 7 days, two piglets from each group were randomly selected to confirm PCV-2 infection. Twenty-one pigs fed by PCV-2-infected sows were randomly divided into three groups and subjected to post-natal PPV infection (group 1), immunostimulation (group 2) or no post-natal treatment (group 3). Twenty-one pigs fed by uninfected sows were also randomly divided and subjected to post-natal PCV-2 and PPV infection (group 4), post-natal PCV-2 infection (group 5) or no treatment (group 6, negative control). Body weight was significantly greater in group 6 than in groups 1, 2 and 4 at 49, 52, 56, 59 and 63 days of age. The typical granulomatous inflammatory reaction and lymphoid depletion of PMWS was observed in the lymph nodes of groups 1, 2 and 4 at 63 days of age. Group 3 had significantly fewer PCV-2-positive cells than groups 1, 2 and 4. In conclusion, PCV-2 shed from colostrum and milk is infectious and reproduces PMWS with post-natal PPV infection or immune stimulation.

Expression of mucins in the mucosal surface of small intestines in 1 week-old pigs.

The aim of this study was to determine the immunoexpression of mucins in jejunal and ileal villous epithelium using six antibodies against MUC1, MUC2, MUC4 MUC5AC, MUC5B and MUC6. The immunohistochemical score for MUC1 has significantly intense staining compared with MUC2 (P=0.008) and the immunohistochemical socre for MUC4 and MUC 6 has significantly intense staining compared with MUC2 (P=0.032) in ileal villous surface. The immunohistochemical score for MUC4 (P=0.008), MUC5AC (P=0.016) and MUC6 (P=0.016) in ileal villous surface has significantly intense staining compared with ileal cryptic surface. The results of this study demonstrated that six mucins gave distinctly different expression patterns throughout the 1 week-old porcine small intestinal tract.