Improvement on Sulfur Capacity of Cu-Al-Based Desulfurization Sorbents with Various Transition Metal Additives for Coal Derived Synthetic Gas Cleaning.

This study examined the effects of additives to improve the COS absorption capacity of Cu-Al-based sorbents for the integrated gasification fuel cell (IGFC) process. To absorb a small amount of COS, an Al-based precursor was added to the precursor solution for Cu-Al-based sorbents because a high surface area absorber was required. Various transition metals (Zn, Fe, Mn) were used as additives to improve the stability of the Cu-Al-based absorbent. The changes in surface properties and sulfur absorption capacity of the Cu-Al-based absorbent were investigated according to the composition of transition metals. As a result of the sulfur absorption test, the difference in the sulfur absorption capacity of the Cu-based sorbents was confirmed depending on the type of additive, and changes in their surface area. Moreover, the pore characteristics were observed by the nitrogen adsorption method. Sorbents with high surface areas generally have high sulfur capacity, but the additive component has a strong effect. These results can be explained by the transition metal additive binding to Cu to form a composite metal oxide. Furthermore, manganese was found to be suitable for improving the stability and surface area of the copper-based absorbent.

Use of Irradiated Homologous Costal Cartilage in Rhinoplasty: Complications in Relation to Graft Location.

BACKGROUND: Nasal septal cartilage and conchal cartilages are preferred sources of grafts in augmentation rhinoplasty. Rib cartilage can also be used, but it may evoke a patient's concerns about a scar and an extensive surgery. In such cases, irradiated homologous costal cartilage (IHCC) can be a useful alternative. However, controversy still exists in many literatures regarding complications with use of IHCC. Therefore, the authors reviewed our experiences with IHCC in rhinoplasty and analyzed the complications in relation to graft location. METHODS: A retrospective chart review was made of all patients who underwent rhinoplasty with IHCC between 2007 and 2015. A total of 323 patients were included. The authors considered the cases that required revision surgery for external aesthetic changes as complications. The authors defined major complications, including resorption, infection, fracture, or warping. RESULTS: The total complication rate was 8%. Two fractures (0.6%), 4 fragmentation (1.2%), 4 resorptions (1.2%), 4 infections (1.2%), and 2 warpings (0.6%) were noted. Most of these complications occurred for the septal extension graft. Other complications, including 1 nasal obstruction, 2 visible contours, 3 caudal septal deviations, and 4 cases of unfavorable results (patient unsatisfactions), were noted. CONCLUSIONS: Based on the outcomes of this study, the authors concluded that IHCC is a useful and reliable source of cartilage graft and can serve as an alternative graft material for rhinoplasty. However, care must be taken in use of IHCC graft in areas under tension such as septal extension graft, though its complication rate is low.

Delicate Structural Control of Si-SiOx-C Composite via High-Speed Spray Pyrolysis for Li-Ion Battery Anodes.

Despite the high theoretical capacity, silicon (Si) anodes in lithium-ion batteries have difficulty in meeting the commercial standards in various aspects. In particular, the huge volume change of Si makes it very challenging to simultaneously achieve high initial Coulombic efficiency (ICE) and long-term cycle life. Herein, we report spray pyrolysis to prepare Si-SiOx composite using an aqueous precursor solution containing Si nanoparticles, citric acid, and sodium hydroxide (NaOH). In the precursor solution, Si nanoparticles are etched by NaOH with the production of [SiO4]4-. During the dynamic course of spray pyrolysis, [SiO4]4- transforms to SiOx matrix and citric acid decomposes to carbon surface layer with the assistance of NaOH that serves as a decomposition catalyst. As a result, a Si-SiOx composite, in which Si nanodomains are homogeneously embedded in the SiOx matrix with carbon surface layer, is generated by a one-pot process with a residence time of only 3.5 s in a flow reactor. The optimal composite structure in terms of Si domain size and Si-to-O ratio exhibited excellent electrochemical performance, such as reversible capacity of 1561.9 mAh g-1 at 0.06C rate and ICE of 80.2% and 87.9% capacity retention after 100 cycles at 1C rate.

Controlled Prelithiation of Silicon Monoxide for High Performance Lithium-Ion Rechargeable Full Cells.

Despite the recent considerable progress, the reversibility and cycle life of silicon anodes in lithium-ion batteries are yet to be improved further to meet the commercial standards. The current major industry, instead, adopts silicon monoxide (SiOx, x ≈ 1), as this phase can accommodate the volume change of embedded Si nanodomains via the silicon oxide matrix. However, the poor Coulombic efficiencies (CEs) in the early period of cycling limit the content of SiOx, usually below 10 wt % in a composite electrode with graphite. Here, we introduce a scalable but delicate prelithiation scheme based on electrical shorting with lithium metal foil. The accurate shorting time and voltage monitoring allow a fine-tuning on the degree of prelithiation without lithium plating, to a level that the CEs in the first three cycles reach 94.9%, 95.7%, and 97.2%. The excellent reversibility enables robust full-cell operations in pairing with an emerging nickel-rich layered cathode, Li[Ni0.8Co0.15Al0.05]O2, even at a commercial level of initial areal capacity of 2.4 mAh cm(-2), leading to a full cell energy density 1.5-times as high as that of graphite-LiCoO2 counterpart in terms of the active material weight.

Nanoparticle-Induced Gelation of Bimodal Slurries with Highly Size-Asymmetric Particles: Effect of Surface Chemistry and Concentration.

A systematic study has been performed to investigate the effect of surface potential of nanoparticles on the rheological behavior of bimodal suspensions, using a model system consisting of polystyrene latex (primary size ∼530 nm) and alumina-coated silica (primary size ∼12 nm) particles. The surface potential of small particles was tuned by varying the solution pH, causing them to be repulsive to each other, attractive to each other, and oppositely charged to the large particles, while the large particles remained electrostatically stabilized. We found that the rheological properties could be dramatically changed from viscous to gel-like depending on the surface potential and concentration of small particles. A colloidal gel was induced by small particles when the small particles had the opposite charge to the large particles and a volume fraction of 10(-4) < ϕsmall < 10(-3), and when the small particles were attractive to each other above a critical threshold, ϕsmall > 10(-4). Cryo-SEM distinguished the gel structures to be either short bridging gels produced by oppositely charged small particles or long bridging gels or dense gels produced by attractive small particles. On the basis of this rheological behavior and microstructure, we prepared a phase diagram of highly size-asymmetric bimodal colloids with respect to the surface chemistry and concentration of small particles.

Structural change and dynamics of colloidal gels under oscillatory shear flow.

The dynamics and rheological behavior of colloidal gels under oscillatory shear flow have been studied by using the Brownian dynamics simulations. The dynamics is studied under the oscillatory shear of small, medium, and large amplitudes. In the small amplitude oscillatory shear (SAOS) regime, the colloidal gel retains a rigid-chain network structure. The colloidal gel oscillates with small structural fluctuations and the elastic stress shows a linear viscoelastic response. In the medium amplitude oscillatory shear (MAOS) regime, the rigid network structure is ruptured, and a negative correlation between the absolute value of strain and the average bond number is observed. The elastic stress shows a transient behavior in between the SAOS and LAOS responses. In the large amplitude oscillatory shear (LAOS) regime, the colloidal gel shows a soft chain structure. Contrary to the negative correlation in the MAOS regime, the colloidal gel shows an oscillating dynamics with a positive correlation between the absolute value of strain and the average bond number. The soft chain structure exhibits no elasticity at small strain, while it shows strong elasticity at large strain. The oscillating dynamics and the rheological behavior are discussed in terms of the microstructural change from the rigid to soft chain structure.

Rheology and microstructure of non-Brownian suspensions in the liquid and crystal coexistence region: strain stiffening in large amplitude oscillatory shear.

Concentrated hard-sphere suspensions in the liquid and crystal coexistence region show a unique nonlinear behavior under a large amplitude oscillatory shear flow, the so-called strain stiffening, in which the viscosity or modulus suddenly starts to increase near a critical strain amplitude. Even though this phenomenon has been widely reported in experiments, its key mechanism has never been investigated in a systematic way. To have a good understanding of this behavior, a numerical simulation was performed using the lattice Boltzmann method (LBM). Strain stiffening was clearly observed at large strain amplitudes, and the critical strain amplitude showed an angular frequency dependency. The distortion of the shear stress appeared near the critical strain amplitude, and the nonlinear behavior was quantified by the Fourier transformation (FT) and the stress decomposition methods. Above the critical strain amplitude, an increase in the global bond order parameter Ψ(6) was observed at the flow reversal. The maximum of Ψ(6) and the maximum shear stress occurred at the same strain. These results show how strongly the ordered structure of the particles is related to the stress distortion. The ordered particles maintained a bond number of "two" with alignment with the compressive axis, and they were distributed over a narrow range of angular distribution (110°-130°). In addition, the ordered structure was formed near the lowest shear rate region (the flow reversal). The characteristics of the ordered structure were remarkably different from those of the hydroclusters which are regarded as the origin of shear thickening. It is clear that strain stiffening and shear thickening originate from different mechanisms. Our results clearly demonstrate how the ordering of the particles induces strain stiffening in the liquid and crystal coexistence region.

High-throughput DNA separation in nanofilter arrays.

We numerically investigated the dynamics of short double-stranded DNA molecules moving through a deep-shallow alternating nanofilter, by utilizing Brownian dynamics simulation. We propose a novel mechanism for high-throughput DNA separation with a high electric field, which was originally predicted by Laachi et al. [Phys. Rev. Lett. 2007, 98, 098106]. In this work, we show that DNA molecules deterministically move along different electrophoretic streamlines according to their length, owing to geometric constraint at the exit of the shallow region. Consequently, it is more probable that long DNA molecules pass over a deep well region without significant lateral migration toward the bottom of the deep well, which is in contrast to the long dwelling time for short DNA molecules. We investigated the dynamics of DNA passage through a nanofilter facilitating electrophoretic field kinematics. The statistical distribution of the DNA molecules according to their size clearly corroborates our assumption. On the other hand, it was also found that the tapering angle between the shallow and deep regions significantly affects the DNA separation performance. The current results show that the nonuniform field effect combined with geometric constraint plays a key role in nanofilter-based DNA separation. We expect that our results will be helpful in designing and operating nanofluidics-based DNA separation devices and in understanding the polymer dynamics in confined geometries.

Lithium-Metal Batteries: From Fundamental Research to Industrialization.

Lithium-metal batteries (LMBs) are representative of post-lithium-ion batteries with the great promise of increasing the energy density drastically by utilizing the low operating voltage and high specific capacity of metallic lithium. LMBs currently stand at a point of transition at which the accumulation of knowledge from fundamental research is being translated into large-scale commercialization. This review summarizes the available strategies for addressing the intrinsic shortcomings of LMBs, such as the suppression of dendritic growth and parasitic reactions from the material to the electrode to the cell level. The discussion pertaining to the cell level includes efforts and concerns relating to scaling up established knowledge and expertise with the view of commercialization. This review intends to encourage researchers in both fundamental research institutions and industry to make a synergistic effort and share their views comprehensively to ensure that LMB technology continues to evolve in harmony to become a mature technology.

Spatial and temporal variations in trophic structure of fish assemblages in the Yellow Sea revealed by C and N stable isotopes.

In this study, we assessed spatial and temporal variations in the trophic structure of fish assemblages in the Yellow Sea during spring and summer 2022 and compared their isotopic niches between the Provisional Measure Zone (PMZ) and Korea's west areas (non-PMZ) within the Yellow Sea. Spatial and temporal differences in the diversity and dominant species of fish assemblages were found between the PMZ and non-PMZ areas between the seasons. The mean δ13C values of fish assemblages were relatively higher in the non-PMZ areas than in the PMZ areas. In contrast, no significant differences were found in the mean δ15N values between the areas. Generally, the isotopic niche indices were relatively narrow in the PMZ areas compared to those in the non-PMZ areas. Overall, these spatial differences between the PMZ and non-PMZ areas suggest different trophic diversity of fish assemblages, resulting from site-specific variations in environmental conditions and community composition.

Simple and reliable light launch from a conventional single-mode fiber into a helical-core fiber through an adiabatically tapered splice.

We propose a simple and efficient light launch scheme for a helical-core fiber (HCF) by using an adiabatically tapered splice technique, through which we overcome its inherent difficulty with light launch owing to the large lateral offset and angular tilt of its core. We experimentally demonstrate single-mode excitation in the HCF in this configuration, which yields the coupling efficiency of around -5.9 dB (26%) for a ~1.1-µm light input when the splice joint is tapered down to 30 µm in diameter. To our knowledge, this is the first proof-of-principle report on the fusion-splice coupling between an HCF and a conventional single-mode fiber.

Biologically based treatment of immature permanent teeth with pulpal necrosis: a case series.

This case series reports the outcomes of 8 patients (ages 9-4 years) who presented with 9 immature permanent teeth with pulpal necrosis and apical periodontitis. During treatment, 5 of the teeth were found to have at least some residual vital tissue remaining in the root canal systems. After NaOCI irrigation and medication with ciprofloxacin, metronidazole, and minocycline, these teeth were sealed with mineral trioxide aggregate and restored. The other group of 4 teeth had no evidence of any residual vital pulp tissue. This second group of teeth was treated with NaOCl irrigation and medicated with ciprofloxacin, metronidazole, and minocycline followed by a revascularization procedure adopted from the trauma literature (bleeding evoked to form an intracanal blood clot). In both groups of patients, there was evidence of satisfactory postoperative clinical outcomes (1-5 years); the patients were asymptomatic, no sinus tracts were evident, apical periodontitis was resolved, and there was radiographic evidence of continuing thickness of dentinal walls, apical closure, or increased root length.

Multilayer deposition on patterned posts using alternating polyelectrolyte droplets in a microfluidic device.

We demonstrate that polyelectrolyte (PE) multilayer thin films deposited on patterned posts with incredibly large numbers of bilayers, which would not be possible with the conventional Layer-by-Layer (LbL) deposition methods, can be obtained in a short process time using alternating polyelectrolyte droplets generated in a microfluidic channel, representing a significant advantage over the conventional processes based on polyelectrolyte deposition followed by the separation of such substrates (typically colloidal particles) with centrifugation and sonication. Positively- and negatively-charged polyelectrolyte droplets were alternatively generated in a microfluidic channel by controlling the capillary number (Ca) as well as the fraction of dispersed phase over the continuous phase. Patterned posts, serving as the substrates for the PE deposition, were created with photo-curable polymers using the optofluidic maskless lithography. The impact of these PE droplets onto the patterned posts allowed the alternative adsorption of PEs, similar to the conventional LbL deposition methods. It was shown that the intensity of fluorescence dye tagged onto (+)-charged PEs adsorbed on the post(s), taken with confocal laser scanning microscopy, increases with deposition time and varies around the post(s). The effect of post shape and interval between the two posts for the droplet-based LbL deposition was also experimentally investigated and analyzed, in connection with the numerical simulations, to elucidate the underlying principles of relevant two-phase flows.

Parametric study of blade tip clearance, flow rate, and impeller speed on blood damage in rotary blood pump.

Phenomenological studies on mechanical hemolysis in rotary blood pumps have provided empirical relationships that predict hemoglobin release as an exponential function of shear rate and time. However, these relations are not universally valid in all flow circumstances, particularly in small gap clearances. The experiments in this study were conducted at multiple operating points based on flow rate, impeller speed, and tip gap clearance. Fresh bovine red blood cells were resuspended in phosphate-buffered saline at about 30% hematocrit, and circulated for 30 min in a centrifugal blood pump with a variable tip gap, designed specifically for these studies. Blood damage indices were found to increase with increased impeller speed or decreased flow rate. The hemolysis index for 50-microm tip gap was found to be less than 200-microm gap, despite increased shear rate. This is explained by a cell screening effect that prevents cells from entering the smaller gap. It is suggested that these parameters should be reflected in the hemolysis model not only for the design, but for the practical use of rotary blood pumps, and that further investigation is needed to explore other possible factors contributing to hemolysis.

Highly Elastic Polyrotaxane Binders for Mechanically Stable Lithium Hosts in Lithium-Metal Batteries.

Despite their unparalleled theoretical capacity, lithium-metal anodes suffer from well-known indiscriminate dendrite growth and parasitic surface reactions. Conductive scaffolds with lithium uptake capacity are recently highlighted as promising lithium hosts, and carbon nanotubes (CNTs) are an ideal candidate for this purpose because of their capability of percolating a conductive network. However, CNT networks are prone to rupture easily due to a large tensile stress generated during lithium uptake-release cycles. Herein, CNT networks integrated with a polyrotaxane-incorporated poly(acrylic acid) (PRPAA) binder via supramolecular interactions are reported, in which the ring-sliding motion of the polyrotaxanes endows extraordinary stretchability and elasticity to the entire binder network. In comparison to a control sample with inelastic binder (i.e., poly(vinyl alcohol)), the CNT network with PRPAA binder can endure a large stress during repeated lithium uptake-release cycles, thereby enhancing the mechanical integrity of the corresponding electrode over battery cycling. As a result, the PRPAA-incorporated CNT network exhibits substantially improved cyclability in lithium-copper asymmetric cells and full cells paired with olivine-LiFePO4 , indicating that high elasticity enabled by mechanically interlocked molecules such as polyrotaxanes can be a useful concept in advancing lithium-metal batteries.

An evaluation of buccal infiltrations and inferior alveolar nerve blocks in pulpal anesthesia for mandibular first molars.

We compared the anesthetic efficacy of inferior alveolar nerve blocks (IANBs) with that of buccal infiltrations (BIs) in mandibular first molars. Using a crossover design, all subjects received a standard IANB or a BI of 1.7 mL of 4% articaine with 1:100,000 adrenaline (Septanest; Septodont, Saint-Maru-des-Fosses, France) on two appointments separated by at least 1 week. Pulpal anesthesia was determined by using an electric pulp tester. Electric pulp testing was repeated at 5, 8, 11, 15, 20, 25, and 30 minutes after the injections. Anesthesia was considered successful if the subject did not respond to the maximum output of the pulp tester at two or more consecutive time points. Fifty-four percent of the BI and 43% of the IANB were successful; the difference was not significant (p = 0.34). The onset of pulpal anesthesia was significantly faster with BI (p = 0.03). In conclusion, BI with 4% articaine for mandibular first molars can be a useful alternative for clinicians because compared with IANB it has a faster onset and a similar success rate.

Electrochemical Synthesis of Ammonia from Water and Nitrogen: A Lithium-Mediated Approach Using Lithium-Ion Conducting Glass Ceramics.

Lithium-mediated reduction of dinitrogen is a promising method to evade electron-stealing hydrogen evolution, a critical challenge which limits faradaic efficiency (FE) and thus hinders the success of traditional protic-solvent-based ammonia electro-synthesis. A viable implementation of the lithium-mediated pathway using lithium-ion conducting glass ceramics involves i) lithium deposition, ii) nitridation, and iii) ammonia formation. Ammonia was successfully synthesized from molecular nitrogen and water, yielding a maximum FE of 52.3 %. With an ammonia synthesis rate comparable to previously reported approaches, the fairly high FE demonstrates the possibility of using this nitrogen fixation strategy as a substitute for firmly established, yet exceedingly complicated and expensive technology, and in so doing represents a next-generation energy storage system.

Clinical Outcomes after Intentional Replantation of Periodontally Involved Teeth.

INTRODUCTION: Periodontal involvement has been thought to be a contraindication for intentional replantation. This retrospective study aimed to assess clinical outcomes after intentional replantation of teeth with periodontal involvement and to explore potential predictors of outcomes. METHODS: Teeth with a history of intentional replantation between March 2000 and December 2014 and with 1 or 2 preoperative periodontal pockets ≥6 mm among 6 sites evaluated per tooth were included. A total of 103 teeth were included, and 74 teeth were followed up for more than 6 months. Outcomes were assessed as improved (a decrease in the number and depths of periodontal pockets and the size of periapical radiolucency and no external root resorption or sign/symptoms) or failed. Data were analyzed with Kaplan-Meier survival analysis and a Cox proportional regression model. RESULTS: Cumulative improved rates declined from 89% at 1 year to 68% at 4 years. A Cox proportional regression model identified the patient's age (P = .049; hazard ratio, 2.552) and the number of preoperative periodontal pockets with a depth ≥6 mm (P = .041; hazard ratio, 2.523) as predictors of outcomes in the replantation of periodontally involved teeth. CONCLUSIONS: Periodontal involvement is not an absolute contraindication to intentional replantation. The teeth with 1 preoperative periodontal pocket ≥6 mm and the subjects aged ≤40 years had 2.5 times and 2.6 times lower probability of failure, respectively, than the teeth with 2 pockets and the subjects aged >40 years. Therefore, these factors need to be carefully considered for intentional replantation.

Effect of Topical Anesthesia on Pain from Needle Insertion and Injection and Its Relationship with Anxiety in Patients Awaiting Apical Surgery: A Randomized Double-blind Clinical Trial.

INTRODUCTION: We aimed to simultaneously investigate the effects of topical anesthesia on needle insertion and injection pain in the labial mucosa of the maxillary central incisors of patients awaiting apical surgery and to assess the relationship between patients' anxiety and pain scores. METHODS: Forty-four patients scheduled for apical surgery of the maxillary anterior incisor or canine were included, and all completed the Modified Dental Anxiety Scale (MDAS) questionnaire. One piece of Xylocaine (AstraZeneca, Sodertalje, Sweden) gauze was applied to the right or left side of the labial vestibule below the central incisor according to a randomization process, and 1 piece of water gauze was applied to the contralateral side of the labial vestibule. Each piece of gauze remained in place for 2 minutes. The subjects were asked to rate their pain according to the numeric rating scale immediately after needle insertion and anesthetic solution injection. RESULTS: Topical anesthetic application significantly reduced both insertion- and injection-related pain. Injection pain was significantly higher than insertion pain throughout the experiment. The difference in pain scores between the placebo and topical anesthetic groups was significantly greater for insertion pain than injection pain. The group with higher MDAS scores showed significantly higher pain scores, except for insertion pain reported by the topical anesthetic group, which did not show a significant difference between MDAS score groups. CONCLUSIONS: The topical anesthetic was highly effective for both insertion and injection pain during infiltration anesthesia in the maxillary central incisors. Highly anxious patients reported higher pain scores; however, topical anesthetics reduced the effect of anxiety on increasing pain.

Proteome Expression in Human Periodontal Ligament after Delayed Hypothermic Preservation.

INTRODUCTION: Previous occasional successes after delayed replantation suggest that the presence of viable cells may not be the only factor for successful periodontal regeneration in delayed replantation. Various other factors such as proteins or the extracellular matrix (ECM) may play a role in this process. The purpose of this study was to characterize changes in the proteome components of periodontal ligament (PDL) tissue after hypothermic preservation of the tooth. METHODS: Extracted teeth were divided into 4 groups: immediate sampling, sampling after 1 week of preservation at 4°C, sampling after 2 weeks of preservation at 4°C, and sampling after 1 week of dry storage at room temperature as a negative control. PDL tissues were collected from the root and stored immediately in liquid nitrogen. The tissues were subjected to 2-dimensional gel electrophoresis, and spot selection was executed. Selected spots that maintained the protein volume were then processed with matrix-assisted laser desorption and ionization time-of-flight mass spectrometry to identify the nature of the proteins. RESULTS: Thirty-five selected spots were analyzed. Sixteen spots were identified as vimentin, and 3 spots were type VI collagen. The size of the 16 vimentin spots decreased gradually with increasing storage time, from 0 to 2 weeks, and decreased rapidly after dry storage. However, only the dry storage group differed significantly from the immediately sampled group. CONCLUSIONS: Vimentin was the most prominent protein followed by type VI collagen in volumetrically maintained protein spots. Although these proteins are known to be closely related with ECM integrity, the role of these proteins in delayed replantation is beyond the scope of this study. Further studies are needed to elucidate the possible role of these proteins for periodontal healing of delayed replantation.